Update to Flutter 1.20.0-7.2.pre (#568)

diff --git a/Dockerfile b/Dockerfile
index bba6715..539beab 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=8fe7655ed20ffd1395f68e30539a847a01a30351
+ARG FLUTTER_COMMIT=a2bde82fbd52e09057a4146f46889f4e10342d32
 
 # We install unzip and remove the apt-index again to keep the
 # docker image diff small.
diff --git a/cloud_run.Dockerfile b/cloud_run.Dockerfile
index 0a4e0fc..18b1df4 100644
--- a/cloud_run.Dockerfile
+++ b/cloud_run.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=8fe7655ed20ffd1395f68e30539a847a01a30351
+ARG FLUTTER_COMMIT=a2bde82fbd52e09057a4146f46889f4e10342d32
 
 # We install unzip and remove the apt-index again to keep the
 # docker image diff small.
diff --git a/flutter b/flutter
index 8fe7655..a2bde82 160000
--- a/flutter
+++ b/flutter
@@ -1 +1 @@
-Subproject commit 8fe7655ed20ffd1395f68e30539a847a01a30351
+Subproject commit a2bde82fbd52e09057a4146f46889f4e10342d32
diff --git a/pubspec.lock b/pubspec.lock
index c8d00b1..0671517 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -14,7 +14,7 @@
       name: _fe_analyzer_shared
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "5.0.0"
+    version: "6.0.0"
   analysis_server_lib:
     dependency: "direct main"
     description:
@@ -28,7 +28,7 @@
       name: analyzer
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.39.13"
+    version: "0.39.14"
   appengine:
     dependency: "direct main"
     description:
@@ -140,7 +140,7 @@
       name: cli_util
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.0"
+    version: "0.1.4"
   code_builder:
     dependency: transitive
     description:
@@ -154,7 +154,7 @@
       name: codemirror
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.5.17+5.54.0"
+    version: "0.5.19+5.56.0"
   collection:
     dependency: transitive
     description:
@@ -273,7 +273,7 @@
       name: http
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.1"
+    version: "0.12.2"
   http2:
     dependency: transitive
     description:
@@ -595,7 +595,7 @@
       name: tuneup
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.3.7"
+    version: "0.3.6+2"
   typed_data:
     dependency: transitive
     description: