sepolicy: Added support for vendor_audio_prop for audio props

Added support for vendor_audio_prop and moved all audio
properties to that type. This is done to conform with Treble
guidelines where vendor domains can access only vendor props.
Added access to only selective domains that need access to
these props.

Change-Id: I3dc6a870255cca258ed72fd9cfa31de392e0f747
CRs-fixed: 2227280