Filter spam notifications

Change-Id: Ibf2377cd7491c7e0e9e9c9657e9e65eef1876ee3
(cherry picked from commit b15ac2d706459e4164790370c4d6ff2f3cc0f41f)

Conflicts:
	packages/SystemUI/AndroidManifest.xml
	packages/SystemUI/res/menu/notification_popup_menu.xml
	packages/SystemUI/src/com/android/systemui/statusbar/BaseStatusBar.java
	services/java/com/android/server/NotificationManagerService.java