3662 [google_maps_flutter_web] update min flutter sdk version to 1.20.0 (cla: yes, p: google_maps_flutter, platform-web, waiting for tree to go green)

3665 [various] Import flutter_test for future compatibility (cla: yes, p: camera, p: in_app_purchase, p: sensors, waiting for tree to go green)

3668 [video_player] fixed misleading size and aspect ratio documentation (cla: yes, p: video_player, waiting for tree to go green)

3669 [Video_Player] Remove the deprecated API reference. (cla: yes, p: video_player, platform-android, waiting for tree to go green)

3676 [image_picker] fix flutter/flutter#71927 (cla: yes, p: image_picker, platform-ios, waiting for tree to go green)