Merge "Show prompt to user to exit split screen" into udc-dev am: 8679a3fd13

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/WallpaperPicker2/+/23141997

Change-Id: Id73f53bf18dc7b2ec052d54c2fd7c38e1abc6945
Signed-off-by: Automerger Merge Worker <[email protected]>