Fix exported property on NotificationBroadcastReceiver.

"exported" property was missing "android:" prefix and as a result was
not being respected.
bug:11367588

Change-Id: I2ec5b39bfb68e652d19d4b619889db9414f01109
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 7ec8007..aabff7b 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -515,7 +515,7 @@
         </receiver>
 
         <!-- BroadcastReceiver for receiving Intents from Notification mechanism. -->
-        <receiver android:name="PhoneApp$NotificationBroadcastReceiver" exported="false">
+        <receiver android:name="PhoneApp$NotificationBroadcastReceiver" android:exported="false">
             <intent-filter>
                 <action android:name="com.android.phone.ACTION_HANG_UP_ONGOING_CALL" />
                 <action android:name="com.android.phone.ACTION_CALL_BACK_FROM_NOTIFICATION" />