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

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



Change-Id: I1e7f4ccc37ec37dc92d558516e2e8c3a80d43c2c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>