[automerger skipped] Merge "Add shell background executor to bubbles and put unregister call on it" into tm-dev am: 0fe75d50 am: d0487d7a am: c24f9923 -s ours am: 3d7030d6 -s ours

am skip reason: Merged-In I2c578d10e0bef49534987be3e82700e50ffd1281 with SHA-1 c679f3d8 is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/18300851



Change-Id: Iec11a974aecefa75d789b8f951afaf8adf775a31
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>