3639 [shared_preferences] Don’t create additional Handler when method channel is called. (cla: yes, p: shared_preferences, platform-android, waiting for tree to go green)

3640 [google_sign_in] Adds support to send clientId as a parameter (cla: yes, p: google_sign_in, platform-android, platform-ios, waiting for tree to go green)

3641 [camera] Stable release for null safety. (cla: yes, nnbd, p: camera)

3642 [extension_google_sign_in_as_googleapis_auth] Migrate to null safety (cla: yes, p: google_sign_in)

3643 [file_selector] Endorse web (cla: yes, p: file_selector)