PEEK [2/2]

Add ability to switch peek on or off.

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>
Change-Id: I1943221aa867099aeed001f3ff54ab83def90391

Conflicts:
	src/com/android/settings/DisplaySettings.java

Conflicts:

	res/values/ras_strings.xml
	src/com/android/settings/DisplaySettings.java