Merge "Avoid double end on PipTransitionAnimator" into udc-dev am: 839aca67

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23270226



Change-Id: I7320837fd9f412449288420fa5a8bda217d7a8ab
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>