Merge "Add @TestApi to UidFrozenStateChanged API surface" into udc-dev am: 59de083813 am: 4c0987c468

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22319600

Change-Id: I6654439accbe18387748c6e06a48a497a78877ef
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>