Add Security Level and the four key states to RkpPoolStats

Attestation pool status is meaningful when it is associated with the
security level of the keymint instance. Counts of the keys in the four
different states are added as fields, by removing the enum.

Ignore-AOSP-First: No mergepath to AOSP.
Bug: 184301651
Test: Statsd test drive script.
Merged-In: I33264d937334cc48b65d5cc59f0522a3a20e512a

Change-Id: I33264d937334cc48b65d5cc59f0522a3a20e512a

stats/atoms.proto

diff --git a/stats/atoms.proto b/stats/atoms.proto
index 2cf236e..9db3331 100644
--- a/stats/atoms.proto
+++ b/stats/atoms.proto
@@ -12383,22 +12383,39 @@
 }
 
 /**
- * Logs: Count of keys in the key pool related to
+ * Logs: Status of the attestation key pool related to
  * Remote Key Provisioning (RKP).
  * Logged from: system/security/keystore2
  */
 message RkpPoolStats {
-    enum PoolStatus {
-        EXPIRING = 1;
-        UNASSIGNED = 2;
-        ATTESTED = 3;
-        TOTAL = 4;
-    }
-    // State of the attestation key pool, for which the count of keys is reported.
-    optional PoolStatus pool_status = 1;
+    /**
+     * Security level of the Keymint instance associated with the
+     * attestation pool status.
+     */
+    optional android.system.security.keystore2.SecurityLevelEnum security_level = 1;
 
-    // Count of keys in the particular status
-    optional int32 count_of_keys = 2;
+    /**
+     * The number of signed attestation certificate chains which are
+     * expired.
+     */
+    optional int32 expiring = 2;
+
+    /**
+     * The number of signed attestation certificate chains which have
+     * not yet been assigned to an app.
+     */
+    optional int32 unassigned = 3;
+
+    /**
+     * The number of signed attestation keys.
+     */
+    optional int32 attested = 4;
+
+    /**
+     * The total number of attestation keys.
+     */
+    optional int32 total = 5;
+
 }
 
 /**