Merge "Do not letterbox the activity in PiP mode" into udc-dev am: 41667fa9 am: 3b341fdb

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23503609



Change-Id: I752d4dd5c7091e61cec8268751357b7a47446400
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>