Merge "Clarified that USER_IDENTIFICATION_ASSOCIATION is optional." into rvc-dev am: b35c0cd494 am: 4ba2b85a44 am: f8bfbb6175 am: ff4e47dfcc

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

Change-Id: Ieb302bb0ebb5d979fcb244b4b752966814da4217