Merge "Add rounded corners to letterbox when taskbar is visible" into tm-qpr-dev am: 3d1c9948

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/20582006



Change-Id: I1db7968142c5ae1c3408d36f3520a9b1ba830b11
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>