Initialize bus volumes at startup

When not running in legacy mode (ie: when we have a bus based audio
HAL), we send down the intial volume to each bus at startup to ensure
that the HAL is aligned with the current Android volume group settings.

Test: Build mojave (tbd testing on bus base device when available)
Bug:  73791816
Change-Id: I41d6103f6f73e6d9a6d3cc7a72c36f6ed9024329
2 files changed