flutter_localization optional package (#12410)

diff --git a/examples/flutter_gallery/pubspec.yaml b/examples/flutter_gallery/pubspec.yaml
index e6b6bba..07291c7 100644
--- a/examples/flutter_gallery/pubspec.yaml
+++ b/examples/flutter_gallery/pubspec.yaml
@@ -21,7 +21,7 @@
 
   args: 0.13.7 # TRANSITIVE DEPENDENCY
   async: 1.13.3 # TRANSITIVE DEPENDENCY
-  barback: 0.15.2+12 # TRANSITIVE DEPENDENCY
+  barback: 0.15.2+13 # TRANSITIVE DEPENDENCY
   charcode: 1.1.1 # TRANSITIVE DEPENDENCY
   cli_util: 0.1.2+1 # TRANSITIVE DEPENDENCY
   convert: 2.0.1 # TRANSITIVE DEPENDENCY