Remove group editing for readonly groups

Bug: 5209461 Uneditable groups (i.e. Circles from G+)
     seems to be editable, even if they aren't

Added a check that removes the edit button in the Group Details
fragment is the group is read-only.

Change-Id: I83b403c6b4b69d86b52827810741e86ace2e8c53
diff --git a/src/com/android/contacts/group/GroupDetailFragment.java b/src/com/android/contacts/group/GroupDetailFragment.java
index 1164069..f54dbd6 100644
--- a/src/com/android/contacts/group/GroupDetailFragment.java
+++ b/src/com/android/contacts/group/GroupDetailFragment.java
@@ -403,10 +403,9 @@
         mOptionsMenuEditable = isGroupEditable() && isVisible();
         mOptionsMenuGroupPresent = isGroupPresent() && isVisible();
 
-        // Editing a group is always possible if a group is selected
-        // TODO: check for external group (member editable) buganizer #5049046
+        // Editing is not possible for read only groups
         final MenuItem editMenu = menu.findItem(R.id.menu_edit_group);
-        editMenu.setVisible(mOptionsMenuGroupPresent);
+        editMenu.setVisible(mOptionsMenuGroupPresent && mOptionsMenuEditable);
 
         final MenuItem deleteMenu = menu.findItem(R.id.menu_delete_group);
         deleteMenu.setVisible(mOptionsMenuEditable);