g2: edit audio configuration

- Collapse primary audio outputs
 * These are exactly the same. Just OR the flags together instead of
   confusing the HAL.
 * This appears to fix the occasional crackle on low-latency streams
   on other devices, so adding it here.
- Enable offload for PCM/AV streaming
- Fix volume control with dynamic volume mixer
- Add back low latency playback

Change-Id: I4134b8250aff8c72ad65685237f2e5dc2eb2eb73
Signed-off-by: bart452 <bart4524@gmail.com>