Android: Turn on errorprone by default

BUG=383646

Change-Id: Ia87d2dff787ffc5e4a59aca1af81a0ac9b727b4a
Reviewed-on: https://chromium-review.googlesource.com/702574Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Commit-Queue: Peter Wen <wnwen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#506831}

build/config/android/config.gni

@@ -137,8 +137,8 @@ if (is_android) {
     # Mark APKs as android:debuggable="true".
     debuggable_apks = !is_official_build
 
-    # Set to true to enable the Errorprone compiler
-    use_errorprone_java_compiler = false
+    # Set to false to disable the Errorprone compiler
+    use_errorprone_java_compiler = true
 
     # Enables EMMA Java code coverage. Instruments classes during build to
     # produce .ec files during runtime