Behavior before this change would turn on mic indicator and then crash (leaving the indicator on indefinitely). Second use case: Allow clients of the API to invoke the service without actually streaming audio. For context see: https://b.corp.google.com/issues/184808866#comment11 BUG: 192938158 BUG: 184808866 Change-Id: I17d1b7e1a489262a034d333fc42fb1dcd45c48c1