Leverage new Audio history sharing for HotwordDetectionService.

The Audio Framework now supports sharing audio history, so
VoiceInteractionManagerService no longer needs to handle audio streams
itself.
See I5beba6c1e489148a14ba86165b8ef2fdc78c802a.

Bug: 168305377
Test: atest CtsVoiceInteractionTestCases
Test: manual
Change-Id: Ia7c5830aa5af6c015ae26619e0a90967ddff74e5