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

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

Change-Id: I19d572c93ab735b01588b41d53f91a6ebc90a202