Merge "Do not letterbox the activity in PiP mode" into udc-dev am: 41667fa9 am: de50e754

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



Change-Id: I13557662b296ae2e2e147498716ed35285ff5229
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>