Merge "Fix extra transition animation played after back gesture trigger." into...

Merge "Fix extra transition animation played after back gesture trigger." into udc-dev am: 58aab277

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22240772



Change-Id: Ia67b02b85815250acc40c93a5db5fc1eb1a936ff
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>