hal: post_proc: add volume based audio calibration support

- add new effect module to listen to volume and device change
- based on volume levels of all streams active over speaker
  compute gain based calibration level and communicate
  with audio HAL to send the same to ACDB loader
- make audio HAL singleton

Bug: 22100304.

Change-Id: If74bf66d32def85022d79ccb9f84c3b85c8a2dc9