Use activity for brightness dialog

Also fixes brightness controller failure to unregister callbacks.

BUG: 15512088
Change-Id: Ia665e006d93391d5a66d4ace614660c4e6d2d5b5
diff --git a/core/java/android/content/Intent.java b/core/java/android/content/Intent.java
index 4153a02..4b5ec48 100644
--- a/core/java/android/content/Intent.java
+++ b/core/java/android/content/Intent.java
@@ -2682,8 +2682,7 @@
             "android.intent.action.QUICK_CLOCK";
 
     /**
-     * Broadcast Action: This is broadcast when a user action should request the
-     * brightness setting dialog.
+     * Activity Action: Shows the brightness setting dialog.
      * @hide
      */
     public static final String ACTION_SHOW_BRIGHTNESS_DIALOG =