2986 [integration_test] Recommend tests to be in integration_test/, fix example (cla: yes)

2988 [shared_preferences] Add shared_preferences_windows (cla: yes)

2991 [webview_flutter] [url_launcher] Handle Multiwindows in WebViews  (cla: yes)

2995 [file_selector_platform_interface] Add platform interface for new file_selector plugin (cla: yes)

2998 [google_maps_flutter_web] Allow Markers with icon:null (cla: yes)

3004 [share] MethodCallHandler.java uses unchecked or unsafe operations (cla: yes)

3015 Add url_launcher_windows (cla: yes)

3016 [in_app_purchase] Fix typo on simulatesAskToBuyInSandBox (cla: yes)