(2/2) Volume Rocker:

* Volume roker wake
* Volume rocker music control

PS6: Indenting the code.
PS7: Redefine strings, keys and variables to more intuitive ones with less fragmentation.

Change-Id: Ie1d883379729ee7011577e3e0cf29ad52914e80c
Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>