3960 Use collection and box literals in ObjC code (cla: yes, p: webview_flutter, p: camera, p: google_maps_flutter, p: image_picker, p: in_app_purchase, platform-ios)

3961 [url_launcher] Fix Link test breakage from shadow DOM changes (cla: yes, p: url_launcher, platform-web)

3964 [multiple_web] Adapt web PlatformView widgets to work slotted. (cla: yes, waiting for tree to go green, p: google_maps_flutter, p: url_launcher, p: video_player, platform-web)

3966 [url_launcher] and [url_launcher_platform_interface] Fix tests broken my ChannelBuffers migration (cla: yes, p: url_launcher)

3967 [quick-actions] Revert migrating integration tests to NNBD (cla: yes, p: quick_actions)