[automerger skipped] Add shell background executor to bubbles and put...

[automerger skipped] Add shell background executor to bubbles and put unregister call on it am: 14a3514a -s ours

am skip reason: Merged-In I2c578d10e0bef49534987be3e82700e50ffd1281 with SHA-1 a7e3899a is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/18357540



Change-Id: Ic624c043ef5aa2afeecb57111e9069b26675fb03
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>