Remove -Werror from deprecated plugin Android builds (flutter#4466)

Now that the default Flutter app template uses a newer compile SDK on Android, the build_all test (which generates an application) is subject to new out-of-band deprecation warnings. For plugins with `-Werror` specified, these are errors, which break CI.

To prevent this, remove `-Werror` from the Android builds of all the deprecated plugins that used it.

Author: stuartmorgan-g

packages/android_alarm_manager/CHANGELOG.md

@@ -2,6 +2,7 @@
 
 * Remove support for the V1 Android embedding.
 * Updated Android lint settings.
+* Removed `-Werror` in Android builds.
 
 ## 2.0.2
 

packages/android_alarm_manager/android/build.gradle

@@ -1,6 +1,6 @@
 group 'io.flutter.plugins.androidalarmmanager'
 version '1.0-SNAPSHOT'
-def args = ["-Xlint:deprecation","-Xlint:unchecked","-Werror"]
+def args = ["-Xlint:deprecation","-Xlint:unchecked"]
 
 buildscript {
     repositories {

packages/android_intent/CHANGELOG.md

@@ -3,6 +3,7 @@
 * Remove references to the V1 Android embedding.
 * Updated Android lint settings.
 * Specify Java 8 for Android build.
+* Removed `-Werror` in Android builds.
 
 ## 2.0.2
 

packages/android_intent/android/build.gradle

@@ -1,6 +1,6 @@
 group 'io.flutter.plugins.androidintent'
 version '1.0-SNAPSHOT'
-def args = ["-Xlint:deprecation","-Xlint:unchecked","-Werror"]
+def args = ["-Xlint:deprecation","-Xlint:unchecked"]
 
 buildscript {
     repositories {

packages/connectivity/connectivity/CHANGELOG.md

@@ -3,6 +3,7 @@
 * Remove references to the Android V1 embedding.
 * Updated Android lint settings.
 * Specify Java 8 for Android build.
+* Removed `-Werror` in Android builds.
 
 ## 3.0.6
 

packages/connectivity/connectivity/android/build.gradle

@@ -1,6 +1,6 @@
 group 'io.flutter.plugins.connectivity'
 version '1.0-SNAPSHOT'
-def args = ["-Xlint:deprecation","-Xlint:unchecked","-Werror"]
+def args = ["-Xlint:deprecation","-Xlint:unchecked"]
 
 buildscript {
     repositories {