Lockscreen blur and blur radius (1/2)

Change-Id: Iab92bc2adfc2c861cd4f1baccdba2409a5deb788

Lockscreen Blur: Disable if music is playing

Some apps don't employ full screen album art.
In that case album art doesn't override wallpaper & content behind screen is clearly visible.
This fixes that issue.

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