Merge "FRR follow-up: address comments in AuthenticationStatsPersister" into udc-qpr-dev am: 83cfc03653 am: 7172f7a979

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/24516053

Change-Id: I1163f8f6989a0d51b0a74fce469f947a790d6e0f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>