Proper getNotificationUri()

Copied getNotificationUri() from mr11 where it was done properly.

Bug: 11533662
Change-Id: I81e200416d5daddac897e6ae9ebdc68abf33e412
diff --git a/src/com/android/mail/browse/ConversationCursor.java b/src/com/android/mail/browse/ConversationCursor.java
index 7975bf6..6df2d18 100644
--- a/src/com/android/mail/browse/ConversationCursor.java
+++ b/src/com/android/mail/browse/ConversationCursor.java
@@ -1946,13 +1946,17 @@
     }
 
     @Override
-    public void setNotificationUri(ContentResolver cr, Uri uri) {
-        throw new UnsupportedOperationException();
+    public Uri getNotificationUri() {
+        if (mUnderlyingCursor == null) {
+            return null;
+        } else {
+            return mUnderlyingCursor.getNotificationUri();
+        }
     }
 
     @Override
-    public Uri getNotificationUri() {
-        return null;
+    public void setNotificationUri(ContentResolver cr, Uri uri) {
+        throw new UnsupportedOperationException();
     }
 
     @Override