3650 Update plugin_platform_interface min version (cla: yes, p: battery, p: camera, p: connectivity, p: device_info, p: file_selector, p: google_maps_flutter, p: image_picker, p: path_provider, p: url_launcher, p: wifi_info_flutter)

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)

3673 [google_maps_flutter_web] Make google_maps_flutter_web work with latest plugins  (cla: yes, p: google_maps_flutter, platform-web)

3675 [google_maps_flutter_web] Move integration tests to example. (cla: yes, p: google_maps_flutter, platform-web)