Forward port 'Swap volume buttons' (2/3)

[mikeioannina]: Adjust for 5.0 changes

Change-Id: I5ed4ae2b7e69e2ada067ed1d3524b3d3fad30e2e
Merge pull request #5 from CyanogenMod/cm-12.0

Forward port 'Swap volume buttons' (2/3)