Settings: Make Safe headset volume handling user configurable (2 of 2)

Patch set 1  : Initial commit
Patch set 2  : Code cleanup and dedupe

Change-Id: I9d46ba5b8ca5a8b18dcb4856c348c86bc3e70899
Merge "Settings: Make Safe headset volume handling user configurable (2 of 2)" into cm-10.1