Merge "Update permission group mapping API doc according to API review." into sc-dev am: bf8849c1 am: f8d88629 am: ff3b23c2

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/14737737

Change-Id: Ifd67bd7e7927c1d82499e058519da339e43d65a9