Merge "bfq: set background cgroup weight to 10" am: e7ee9c19e2

Original change: https://android-review.googlesource.com/c/platform/system/core/+/1605121

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I3df84dea68e8cd5f5df4dfc7b649ce8744643a56