Merge "Move the pinned task to front when dismissed split-screen" into rvc-dev...

Merge "Move the pinned task to front when dismissed split-screen" into rvc-dev am: 92d8d6c3 am: c10b144b am: 851bd1f9 am: f1ace3cd

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/12034169

Change-Id: I70c90d33a16d39b8c8924078dda9b7fccd013ada