DSPManager: Remove unused strings

Change-Id: I1355c80161ac0a005eae563f6b2bcf1dde21f192
Merge remote-tracking branch 'cm/cm-11.0' into HEAD

Conflicts:
	res/values/strings.xml

Change-Id: I9060557cd55ef02a7982b5337ecc39b7b6ed4a4b