chore(docs): Add new discovery artifacts and reference documents
diff --git a/docs/dyn/apigee_v1.organizations.environments.html b/docs/dyn/apigee_v1.organizations.environments.html
index eec6e57..84e5d80 100644
--- a/docs/dyn/apigee_v1.organizations.environments.html
+++ b/docs/dyn/apigee_v1.organizations.environments.html
@@ -474,6 +474,7 @@
       "host": "A String", # Host name of the target server.
       "name": "A String", # Target server revision name in the following format: `organizations/{org}/environments/{env}/targetservers/{targetserver}/revisions/{rev}`
       "port": 42, # Port number for the target server.
+      "protocol": "A String", # The protocol used by this target server.
       "tlsInfo": { # TLS settings for the target server.
         "ciphers": [ # List of ciphers that are granted access.
           "A String",
diff --git a/docs/dyn/apigee_v1.organizations.environments.targetservers.html b/docs/dyn/apigee_v1.organizations.environments.targetservers.html
index 40e2727..19d300b 100644
--- a/docs/dyn/apigee_v1.organizations.environments.targetservers.html
+++ b/docs/dyn/apigee_v1.organizations.environments.targetservers.html
@@ -110,6 +110,7 @@
   "isEnabled": True or False, # Optional. Enabling/disabling a TargetServer is useful when TargetServers are used in load balancing configurations, and one or more TargetServers need to taken out of rotation periodically. Defaults to true.
   "name": "A String", # Required. The resource id of this target server. Values must match the regular expression
   "port": 42, # Required. The port number this target connects to on the given host. Value must be between 1 and 65535, inclusive.
+  "protocol": "A String", # Immutable. The protocol used by this TargetServer.
   "sSLInfo": { # TLS configuration information for VirtualHosts and TargetServers. # Optional. Specifies TLS configuration info for this TargetServer. The JSON name is `sSLInfo` for legacy/backwards compatibility reasons -- Edge originally supported SSL, and the name is still used for TLS configuration.
     "ciphers": [ # The SSL/TLS cipher suites to be used. Must be one of the cipher suite names listed in: http://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html#ciphersuites
       "A String",
@@ -145,6 +146,7 @@
   "isEnabled": True or False, # Optional. Enabling/disabling a TargetServer is useful when TargetServers are used in load balancing configurations, and one or more TargetServers need to taken out of rotation periodically. Defaults to true.
   "name": "A String", # Required. The resource id of this target server. Values must match the regular expression
   "port": 42, # Required. The port number this target connects to on the given host. Value must be between 1 and 65535, inclusive.
+  "protocol": "A String", # Immutable. The protocol used by this TargetServer.
   "sSLInfo": { # TLS configuration information for VirtualHosts and TargetServers. # Optional. Specifies TLS configuration info for this TargetServer. The JSON name is `sSLInfo` for legacy/backwards compatibility reasons -- Edge originally supported SSL, and the name is still used for TLS configuration.
     "ciphers": [ # The SSL/TLS cipher suites to be used. Must be one of the cipher suite names listed in: http://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html#ciphersuites
       "A String",
@@ -186,6 +188,7 @@
   "isEnabled": True or False, # Optional. Enabling/disabling a TargetServer is useful when TargetServers are used in load balancing configurations, and one or more TargetServers need to taken out of rotation periodically. Defaults to true.
   "name": "A String", # Required. The resource id of this target server. Values must match the regular expression
   "port": 42, # Required. The port number this target connects to on the given host. Value must be between 1 and 65535, inclusive.
+  "protocol": "A String", # Immutable. The protocol used by this TargetServer.
   "sSLInfo": { # TLS configuration information for VirtualHosts and TargetServers. # Optional. Specifies TLS configuration info for this TargetServer. The JSON name is `sSLInfo` for legacy/backwards compatibility reasons -- Edge originally supported SSL, and the name is still used for TLS configuration.
     "ciphers": [ # The SSL/TLS cipher suites to be used. Must be one of the cipher suite names listed in: http://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html#ciphersuites
       "A String",
@@ -227,6 +230,7 @@
   "isEnabled": True or False, # Optional. Enabling/disabling a TargetServer is useful when TargetServers are used in load balancing configurations, and one or more TargetServers need to taken out of rotation periodically. Defaults to true.
   "name": "A String", # Required. The resource id of this target server. Values must match the regular expression
   "port": 42, # Required. The port number this target connects to on the given host. Value must be between 1 and 65535, inclusive.
+  "protocol": "A String", # Immutable. The protocol used by this TargetServer.
   "sSLInfo": { # TLS configuration information for VirtualHosts and TargetServers. # Optional. Specifies TLS configuration info for this TargetServer. The JSON name is `sSLInfo` for legacy/backwards compatibility reasons -- Edge originally supported SSL, and the name is still used for TLS configuration.
     "ciphers": [ # The SSL/TLS cipher suites to be used. Must be one of the cipher suite names listed in: http://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html#ciphersuites
       "A String",
@@ -263,6 +267,7 @@
   "isEnabled": True or False, # Optional. Enabling/disabling a TargetServer is useful when TargetServers are used in load balancing configurations, and one or more TargetServers need to taken out of rotation periodically. Defaults to true.
   "name": "A String", # Required. The resource id of this target server. Values must match the regular expression
   "port": 42, # Required. The port number this target connects to on the given host. Value must be between 1 and 65535, inclusive.
+  "protocol": "A String", # Immutable. The protocol used by this TargetServer.
   "sSLInfo": { # TLS configuration information for VirtualHosts and TargetServers. # Optional. Specifies TLS configuration info for this TargetServer. The JSON name is `sSLInfo` for legacy/backwards compatibility reasons -- Edge originally supported SSL, and the name is still used for TLS configuration.
     "ciphers": [ # The SSL/TLS cipher suites to be used. Must be one of the cipher suite names listed in: http://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html#ciphersuites
       "A String",
@@ -297,6 +302,7 @@
   "isEnabled": True or False, # Optional. Enabling/disabling a TargetServer is useful when TargetServers are used in load balancing configurations, and one or more TargetServers need to taken out of rotation periodically. Defaults to true.
   "name": "A String", # Required. The resource id of this target server. Values must match the regular expression
   "port": 42, # Required. The port number this target connects to on the given host. Value must be between 1 and 65535, inclusive.
+  "protocol": "A String", # Immutable. The protocol used by this TargetServer.
   "sSLInfo": { # TLS configuration information for VirtualHosts and TargetServers. # Optional. Specifies TLS configuration info for this TargetServer. The JSON name is `sSLInfo` for legacy/backwards compatibility reasons -- Edge originally supported SSL, and the name is still used for TLS configuration.
     "ciphers": [ # The SSL/TLS cipher suites to be used. Must be one of the cipher suite names listed in: http://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html#ciphersuites
       "A String",
diff --git a/docs/dyn/apigee_v1.organizations.instances.html b/docs/dyn/apigee_v1.organizations.instances.html
index 3e062ba..15186ac 100644
--- a/docs/dyn/apigee_v1.organizations.instances.html
+++ b/docs/dyn/apigee_v1.organizations.instances.html
@@ -93,7 +93,7 @@
   <code><a href="#close">close()</a></code></p>
 <p class="firstline">Close httplib2 connections.</p>
 <p class="toc_element">
-  <code><a href="#create">create(parent, body=None, environments=None, x__xgafv=None)</a></code></p>
+  <code><a href="#create">create(parent, body=None, x__xgafv=None)</a></code></p>
 <p class="firstline">Creates an Apigee runtime instance. The instance is accessible from the authorized network configured on the organization. **Note:** Not supported for Apigee hybrid.</p>
 <p class="toc_element">
   <code><a href="#delete">delete(name, x__xgafv=None)</a></code></p>
@@ -117,7 +117,7 @@
 </div>
 
 <div class="method">
-    <code class="details" id="create">create(parent, body=None, environments=None, x__xgafv=None)</code>
+    <code class="details" id="create">create(parent, body=None, x__xgafv=None)</code>
   <pre>Creates an Apigee runtime instance. The instance is accessible from the authorized network configured on the organization. **Note:** Not supported for Apigee hybrid.
 
 Args:
@@ -139,7 +139,6 @@
   &quot;state&quot;: &quot;A String&quot;, # Output only. State of the instance. Values other than `ACTIVE` means the resource is not ready to use.
 }
 
-  environments: string, Optional. List of environments that will be attached to the instance during creation. (repeated)
   x__xgafv: string, V1 error format.
     Allowed values
       1 - v1 error format
diff --git a/docs/dyn/apigee_v1.projects.html b/docs/dyn/apigee_v1.projects.html
index 998dc12..4de4c01 100644
--- a/docs/dyn/apigee_v1.projects.html
+++ b/docs/dyn/apigee_v1.projects.html
@@ -98,7 +98,7 @@
 { # Request for ProvisionOrganization.
   &quot;analyticsRegion&quot;: &quot;A String&quot;, # Primary Cloud Platform region for analytics data storage. For valid values, see [Create an organization](https://cloud.google.com/apigee/docs/hybrid/latest/precog-provision). Defaults to `us-west1`.
   &quot;authorizedNetwork&quot;: &quot;A String&quot;, # Name of the customer project&#x27;s VPC network. If provided, the network needs to be peered through Service Networking. If none is provided, the organization will have access only to the public internet.
-  &quot;runtimeLocation&quot;: &quot;A String&quot;, # Cloud Platform location for the runtime instance. Defaults to `us-west1-a`.
+  &quot;runtimeLocation&quot;: &quot;A String&quot;, # Cloud Platform location for the runtime instance. Defaults to zone `us-west1-a`. If a region is provided, `EVAL` organizations will use the region for automatically selecting a zone for the runtime instance.
 }
 
   x__xgafv: string, V1 error format.
diff --git a/docs/dyn/privateca_v1beta1.projects.locations.html b/docs/dyn/privateca_v1beta1.projects.locations.html
index 3a813e5..92cbae1 100644
--- a/docs/dyn/privateca_v1beta1.projects.locations.html
+++ b/docs/dyn/privateca_v1beta1.projects.locations.html
@@ -141,7 +141,7 @@
 Args:
   name: string, The resource that owns the locations collection, if applicable. (required)
   filter: string, A filter to narrow down results to a preferred subset. The filtering language accepts strings like &quot;displayName=tokyo&quot;, and is documented in more detail in [AIP-160](https://google.aip.dev/160).
-  pageSize: integer, The maximum number of results to return. If not set, the service will select a default.
+  pageSize: integer, The maximum number of results to return. If not set, the service selects a default.
   pageToken: string, A page token received from the `next_page_token` field in the response. Send that page token to receive the subsequent page.
   x__xgafv: string, V1 error format.
     Allowed values