Merge "Attach PipSnapshotContentOverlay in PipTransition" into udc-dev am: 83efc2a1 am: fef65415 am: 93b06fa5

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23374940



Change-Id: I73f70444fe8a50dc679a6eea8d11feac7a3f1175
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>