Merge "Show battery percentage in QS header" into udc-dev am: a9ab5cc786 am: 7bc96de827

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23681798

Change-Id: Iaeb64dae85668809c3a5d40041df292a28b34922
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>