4108 Add Basic Junit Tests to some plugins (cla: yes, p: webview_flutter, p: google_sign_in, p: local_auth, p: video_player, p: shared_preferences, platform-android)

4137 [various] Prepare plugin repo for binding API improvements (cla: yes, waiting for tree to go green, p: battery, p: webview_flutter, p: camera, p: video_player, p: sensors, p: connectivity)

4141 [video_player] Update to ExoPlayer 2.14.1 (cla: yes, p: video_player, platform-android)

4148 [various] Prepare plugin repo for binding API improvements (cla: yes, waiting for tree to go green, p: camera, p: video_player)