Merge "Apply root task for launch activity animation." into udc-dev am:...

Merge "Apply root task for launch activity animation." into udc-dev am: 181bcdba am: 2ff43a98 am: de898182 am: 7e88c178

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23109637



Change-Id: Ie3ad963f2b064380633af7b170a681367c29a743
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>