4434 [in_app_purchase] Update to the latest pkg:json_serializable (cla: yes, p: in_app_purchase, platform-ios, platform-android)

p: google_maps_flutter - 17 pull request(s)

2443 Uncomment Marker icons now that ImageListener API change has landed in stable (cla: yes, waiting for tree to go green, p: google_maps_flutter, last mile)

2653 [google_maps_flutter] Marker dragging events (cla: yes, in review, p: google_maps_flutter, needs tests)

2838 Google maps marker drag events impl (cla: yes, p: google_maps_flutter, platform-ios, platform-android)

4082 Support Hybrid Composition through the GoogleMaps Widget (cla: yes, p: google_maps_flutter)