Add hotword stream configuration to AudioRecord

In order to enable AGSA Natural Conversation, the AudioRecord API
needs to be able to express opening streams that provide content
from the hotword pipeline, and/or content which represents audio
captured a short duration in the past.

Test: atest AudioRecordTest, ST smoke test
Bug: 237449755
Change-Id: I570d0fa6059a3fcdd9532b04a42a75acddbeabe3