AudioService: fix safe volume enforced even when disabled

On onConfigureSafeVolume, the proper API was not used, leading
to the setting not being respected. Sometimes after boot, the
heaadset volume will be set back to the safe volume.

Change-Id: I5ba8bb1a18ce97ed64646663c7e75cb277356778
Merge pull request #3 from CyanogenMod/cm-11.0

AudioService: fix safe volume enforced even when disabled