[API] Introduce API for accessibility data stream

We provide an API to egress necessary data in the from of bytes only
when the accessibility setting is turned on for VisualQueryDetector. The
use of this API should be strictly reviewed and should only be used to
egress visual data related to accessibility features. Design:
go/vqds-vic-design

Bug: 318617199
Test: atest CtsVoiceInteractionTestCases
Flag: ACONFIG android.service.voice.flags.allow_complex_results_egress_from_vqds NEXTFOOD
Change-Id: I295bd8818058af8c89ce73c82d9c12ca22d367df