Merge "Clarified that USER_IDENTIFICATION_ASSOCIATION is optional." into rvc-dev am: b35c0cd494 am: 4ba2b85a44

Original change: https://googleplex-android-review.googlesource.com/c/platform/hardware/interfaces/+/11796048

Change-Id: I9722dcdf68e99bd8e3c41880dc9c5f07a1cd5757