Merge "Fix no back animations when the target window is animating" into udc-dev am: 2d7ffd6e am: eb96cb6b

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/21533471



Change-Id: I0f57af01b56767ca4649814f15168e1466eba50e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>