Lockscreen Blur: Allow setting blur radius (1/2)

This commti was Re-committed by @Namja in Triangles

Change-Id: Ie70102605e4c7b29917b3ebb81a2dd567a1eaa60

Conflicts:
	core/java/android/provider/Settings.java
	packages/Keyguard/src/com/android/keyguard/KeyguardViewManager.java