Update Flutter to 1.19.0-4.1.pre (#563)

diff --git a/Dockerfile b/Dockerfile
index f14b588..a84fe4c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -6,7 +6,7 @@
 # To retrieve this value, please run the following in your closest shell:
 #
 # $ (cd flutter && git rev-parse HEAD)
-ARG FLUTTER_COMMIT=2738a1148ba6c9a6114df62358109407c3ef2553
+ARG FLUTTER_COMMIT=f994b769743368b36b9c03fb359f62230b60ab92
 
 # We install unzip and remove the apt-index again to keep the
 # docker image diff small.
diff --git a/flutter b/flutter
index 2738a11..f994b76 160000
--- a/flutter
+++ b/flutter
@@ -1 +1 @@
-Subproject commit 2738a1148ba6c9a6114df62358109407c3ef2553
+Subproject commit f994b769743368b36b9c03fb359f62230b60ab92
diff --git a/pubspec.lock b/pubspec.lock
index 2d477ec..97498fe 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -7,14 +7,14 @@
       name: _discoveryapis_commons
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.1.9"
+    version: "0.2.0"
   _fe_analyzer_shared:
     dependency: transitive
     description:
       name: _fe_analyzer_shared
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.0.0"
+    version: "4.0.0"
   analysis_server_lib:
     dependency: "direct main"
     description:
@@ -28,7 +28,7 @@
       name: analyzer
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.39.8"
+    version: "0.39.10"
   appengine:
     dependency: "direct main"
     description:
@@ -56,7 +56,7 @@
       name: bazel_worker
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.1.23+1"
+    version: "0.1.24"
   boolean_selector:
     dependency: transitive
     description:
@@ -91,7 +91,7 @@
       name: build_resolvers
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.8"
+    version: "1.3.9"
   build_runner:
     dependency: "direct dev"
     description:
@@ -140,21 +140,21 @@
       name: cli_util
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.1.4"
+    version: "0.2.0"
   code_builder:
     dependency: transitive
     description:
       name: code_builder
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.2.1"
+    version: "3.3.0"
   codemirror:
     dependency: "direct dev"
     description:
       name: codemirror
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.5.16+5.53.0"
+    version: "0.5.17+5.54.0"
   collection:
     dependency: transitive
     description:
@@ -175,14 +175,14 @@
       name: coverage
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.13.9"
+    version: "0.13.11"
   crypto:
     dependency: "direct main"
     description:
       name: crypto
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.4"
+    version: "2.1.5"
   csslib:
     dependency: transitive
     description:
@@ -217,7 +217,7 @@
       name: gcloud
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.7.0+1"
+    version: "0.7.2"
   glob:
     dependency: transitive
     description:
@@ -238,7 +238,7 @@
       name: googleapis_auth
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.11+1"
+    version: "0.2.12"
   graphs:
     dependency: transitive
     description:
@@ -252,7 +252,7 @@
       name: grinder
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.8.4"
+    version: "0.8.5"
   grpc:
     dependency: transitive
     description:
@@ -329,7 +329,7 @@
       name: js
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.6.1+1"
+    version: "0.6.2"
   json_annotation:
     dependency: transitive
     description:
@@ -399,7 +399,7 @@
       name: node_preamble
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.4.8"
+    version: "1.4.12"
   package_config:
     dependency: transitive
     description:
@@ -574,21 +574,21 @@
       name: test
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.14.3"
+    version: "1.14.7"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.15"
+    version: "0.2.16"
   test_core:
     dependency: transitive
     description:
       name: test_core
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.3.4"
+    version: "0.3.7"
   timing:
     dependency: transitive
     description:
@@ -602,7 +602,7 @@
       name: tuneup
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.3.6+2"
+    version: "0.3.7"
   typed_data:
     dependency: transitive
     description:
@@ -623,7 +623,7 @@
       name: vm_service
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "4.0.4"
+    version: "4.1.0"
   watcher:
     dependency: transitive
     description:
@@ -644,7 +644,7 @@
       name: webkit_inspection_protocol
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.5.4"
+    version: "0.7.3"
   yaml:
     dependency: "direct main"
     description: