Move volume adjust sound option to more native place (2/2).

Our new UX concept includes saving more settings headers possible.
Move this into Volumes settings fragment. Also update description string.

PS2: Update description string.

Credits: Carlo Savignano <stevewatersy@gmail.com>

Conflicts:
	res/values/pa_strings.xml

Change-Id: I41d46d3f6a4fcf82db2489af9f85f28ab754a8e2