Merge "Change ASSISTANT_SESSION_UNKNOWN ID" into rvc-qpr-dev am: d0cf46f6f3 am: 003989a2f3

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/12345488

Change-Id: I996f7c730b04fec60f0e864e7e5816e5d02e272a