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)

3652 [connectivity_for_web] Migration to null-safety. (cla: yes, p: connectivity, platform-web, waiting for tree to go green)

3659 [android_intent] move unit test to nullsafety (cla: yes, p: android_intent, waiting for tree to go green)

3660 [share] Migrate unit tests to null-safety. (cla: yes, p: share, waiting for tree to go green)

3661 Remove unused plugin (integration_test_macos) (cla: yes, p: integration_test, platform-macos, waiting for tree to go green)