Merge "Add documentation to QSTileRevealController" into tm-qpr-dev am: c5c52e05 am: 8ab66503

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/19754102



Change-Id: I58e0041d81716d424002bd4ef7adb12b31485dd2
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>