Merge "Add a device config namespace for battery_stats" into udc-dev am: 01d61c38 am: 665af3d9

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/21780255



Change-Id: I3b3d7ad01338f86c22ccbf2045aa394472dcaa23
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>