Merge "Add a TaskState tracking mechanism to Recents transition" into udc-dev am: 07825b19

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/21497560



Change-Id: Ib3fdc550cdb74c7ebc0723cbc4a28cd8f1bbccdc
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>