Merge "Do not throw exception on task vanished" into tm-qpr-dev am: e572351d am: 1df1042d am: 83dde0bc am: d19a47f0

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22333702



Change-Id: Id35b8dc016707e75cefde596f4379f314661ecc2
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>