Merge "Make PiP round corners when entering from split screen." into tm-dev am: 0b6bf0f2 am: 8a876b25 am: 1dd5670a

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



Change-Id: Ie7ef1d03679de78ce4583548fe4681ce51d729aa
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>