1668 [firebase_database]Add missing template type parameter to  calls. Bump minimum Flutter v… (cla: yes)

1669 [firebase_dynamic_links]Add missing template type parameter to  calls. Bump minimum Flutter v… (cla: yes)

1670 [firebase_messaging]Add missing template type parameter to invokeMethod calls. Bump minimum Flutter version to 1.5.0. Replace invokeMethod with invokeMapMethod wherever necessary. (cla: yes)

1671 [firebase_ml_vision] Add missing template type parameter to invokeMethod calls. Bump minimum Flutter version to 1.5.0. Replace invokeMethod with invokeMapMethod wherever necessary. (cla: yes)

1672 [local_auth] The thread for executor needs to be UI thread. (cla: yes)

1674 [google_maps_flutter] Adds support for add padding to the map (cla: yes)