[file_selector]Improve API docs and examples (flutter#4824)

[camera] Publish federated implementations (flutter#5942)

[camera] Federate mobile implementations (flutter#5937)

[camera] Federate mobile implementations (flutter#5937)

Ignore upcoming warnings webview_flutter_android (flutter#5922)

* ignore upcoming warnings in webview_flutter_android

* update-release-info

[url_launcher] Update README discussion of permissions (flutter#5424)

[various] Clean up obsolete references to "master" (flutter#5912)

[various] Clean up obsolete references to "master" (flutter#5912)

[video_player] Android: Rotate videos recorded in landscapeRight (flu…

…tter#3820)

[various] Clean up obsolete references to "master" (flutter#5912)