Move CEC volume control setting to CEC config

Migrate HdmiControlManager#(get|is)HdmiCecVolumeControlEnabled to use
the new HdmiCecConfig.

This config is backed by an integer, the volume control enabled states
are migrated from boolean values to a new IntDef. Listeners also return
these integer values.

Bug: 172819080
Test: atest com.android.server.hdmi
Change-Id: I0e1fb46886f89f143bb830494ab23602301e3d8e