[Samples] Add IGameNotification.Data property so data can be set in a cross-platform fashion (thanks to @jorrit5477).
[Samples] Add retrieval of notification enabled status on Android (thanks to @jorrit5477).
[Samples] Add cross-platform retrieval of the last notification (thanks to @jorrit5477).
Notes to tester
Check whether AndroidNotificationsPlatform.GetLastNotification() and iOSNotificationsPlatform.GetLastNotification() works (send some notifications and check if the last one can be retrieved).
Changes
Notes to tester