Ensure example app uses fixed API too.

Author: ditman

packages/google_maps_flutter/google_maps_flutter_web/example/pubspec.yaml

@@ -14,7 +14,7 @@ dependencies:
 
 dev_dependencies:
   build_runner: ^2.1.1
-  google_maps: ^5.1.0
+  google_maps: ^5.2.0
   google_maps_flutter: # Used for projection_test.dart
     path: ../../google_maps_flutter
   http: ^0.13.0