Improve error handling for Trusted Hotword

Add a new callback with an DetectorFailure parameter to let the
assistant know what went wrong during using the hotword detector.

Bug: 256780491
Bug: 261012843
Test: atest CtsVoiceInteractionTestCases

Change-Id: I0b7d9625abfa10f93ad8564e85faedd1db4fa51d
14 files changed