Settings: Lockscreen custom wallpaper (2/2)
- created a listpreference which changes the lockscreen background style (eg.
Color Fill, Custom Image and default)
- using the switch the preference for alpha seekbar (custom image only) or
ColorPreferencePicker switches.

*added necessary colorpicker java files and seekbar java

Change-Id: I1ac1351e9a31a5827847e30113e933f2b7da219f

Conflicts:
	res/values/cm_arrays.xml
	res/values/cm_strings.xml