Merge "Remove stage concept from split screen APIs" into tm-qpr-dev am: f876fb99

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/20112690



Change-Id: I42ed6f2407e91834769912430c1155c2971d3082
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>