Merge "Only run Animation#setBackdropColor on overriden app transition" into tm-dev am: 2b70f83f

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17983851



Change-Id: I82d9d7f6329f89318e5f8e081b6d1d0d1e55c672
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>