CSD: Implement support for absolute volume

Devices with absolute volume will query the volume curves and apply the
given attenuation on the internal MEL computation.

Test: dumpsys and logs
Bug: 265928284
Change-Id: Ia126547e40cad0d8abdf740d7880502a5c82c36f
Merged-In: Ia126547e40cad0d8abdf740d7880502a5c82c36f