Zen: Simplify notification policy api, add zenmode api.

 - Remove the concept of a notification policy management token
   in favor of a simple grant/deny per app.  Currently, all requests
   are immediately granted.
 - Add zen mode getter/setting, limit to apps that have been granted
   policy access.
 - Add intent for zen mode changes.
 - Public name for zen mode = "interruption filter", moved from
   NotificationListenerService to NotificationManager.
 - Add settings metadata for new DND access Settings screen.
 - Add the split sender settings for calls vs messages to the public
   Policy api.
 - This change is meant to finalize the public api, persisting
   granted app status and showing the user-visible dialog will be
   done as followups.

Bug: 18298798
Change-Id: I511be98d69939f057c0c7dc1a6dfe63d1c468193
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index 7c3c11b..dc70d7b 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -809,6 +809,18 @@
             = "android.settings.ACTION_NOTIFICATION_LISTENER_SETTINGS";
 
     /**
+     * Activity Action: Show Do Not Disturb access settings.
+     * <p>
+     * In some cases, a matching Activity may not exist, so ensure you safeguard against this.
+     * <p>
+     * Input: Nothing.
+     * <p>
+     * Output: Nothing.
+     */
+    @SdkConstant(SdkConstantType.ACTIVITY_INTENT_ACTION)
+    public static final String ACTION_ZEN_ACCESS_SETTINGS = "android.settings.ZEN_ACCESS_SETTINGS";
+
+    /**
      * @hide
      */
     @SdkConstant(SdkConstantType.ACTIVITY_INTENT_ACTION)