3932 Move integration test to null safety for multiple plugins (cla: yes, p: webview_flutter, p: image_picker, p: in_app_purchase, p: wifi_info_flutter, p: quick_actions, p: connectivity, p: device_info, platform-ios, platform-android, platform-macos)

3934 Enable NNBD for more plugin integration tests (cla: yes, p: camera, p: google_maps_flutter, p: local_auth, p: url_launcher, p: shared_preferences, platform-windows, platform-macos, platform-linux)

3941 [connectivity] Ignore Reachability pointer to int cast warning (cla: yes, p: connectivity, platform-ios, platform-macos)

3949 [integration_test] Remove the package (cla: yes, waiting for tree to go green, p: integration_test, platform-ios, platform-android, platform-macos, platform-web)