Allow signature apps to modify notification policies.

Bug: 22977552
Change-Id: Ib2bc3a55a904011218bb3adb19998cc4a0b7e709
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index c713454..cf4e4f6 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -2530,6 +2530,12 @@
         android:label="@string/permlab_access_notification_policy"
         android:protectionLevel="normal" />
 
+    <!-- Allows modification of do not disturb rules and policies. Only allowed for system
+        processes.
+        @hide -->
+    <permission android:name="android.permission.MANAGE_NOTIFICATIONS"
+                android:protectionLevel="signature" />
+
     <!-- Allows access to keyguard secure storage.  Only allowed for system processes.
         @hide -->
     <permission android:name="android.permission.ACCESS_KEYGUARD_SECURE_STORAGE"