HeadsUp: Add heads up blacklist options. (1/2)

Change-Id: If9e5eed658871400b3c21d9354262e0887bc592e

Conflicts:
	core/java/android/provider/Settings.java
	packages/SettingsProvider/res/values/defaults.xml
	packages/SystemUI/src/com/android/systemui/statusbar/BaseStatusBar.java