[2/2] settings: expandable volume panel and tweaks
Setting to disable volume adjust sounds (VOLUME_ADJUST_SOUNDS_ENABLED)
This is so annoying :)

Enhanced dialog to add checkbox for unlinking ringer and
notification volume (VOLUME_LINK_NOTIFICATION)

EDIT:
No idea why google changed the order
Media is now above ringer but in volume panel
its different. So which one to change? :)

Change-Id: Ia30bbb1c2f44d0c21cd08748bd552685810f960f

(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>