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)

3950 [in_app_purchase_ios] Add Restore purchases button to example (cla: yes, p: in_app_purchase, platform-ios)

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)

3976 [in_app_purchase] Revert changes from PR 3897 (cla: yes, p: in_app_purchase, platform-ios)