Merge "Transitions can also be aborted after start." into tm-qpr-dev am: 73fb86b1 am: 252bb3e6

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/20315964



Change-Id: I3fe158cae911e78caa6a3016cca5372a0e79d346
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>