Change directory permission to "signature|system"

Change-Id: I53dea6984b4577803fdead5caad0112503d2b4e5

Author: Subir Jhanb

core/res/AndroidManifest.xml

@@ -283,7 +283,7 @@
     <!-- @hide -->
     <permission android:name="android.permission.BIND_DIRECTORY_SEARCH"
         android:permissionGroup="android.permission-group.PERSONAL_INFO"
-        android:protectionLevel="signature" />
+        android:protectionLevel="signature|system" />
 
     <!-- Allows an application to read the user's call log. -->
     <permission android:name="android.permission.READ_CALL_LOG"