Merge "Make PiP round corners when entering from split screen." into tm-dev am: 0b6bf0f2

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17627555



Change-Id: Idc289d28a57718c837fd3e16f1db2841a301e855
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>