Merge "Fix the race condition between creating and killing process group" into udc-dev am: c601737f am: b57cb2a0 am: fe1a89e5

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22970327



Change-Id: Ic2888a1f02f84588dbe2fb1a966b1bcfb3691ade
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>