As resource group is a shared object, so it can't be run in a transnational block. With the current implementation if user change the name and any other parameter it will throw an error message as two ALTER statement can't run in a transnational block.
I have fixed the issue. I have modified the logic and add one more text box in SQL tab on "Resource Group" dialog as we have in "New Database" dialog.
Attached is the patch file of the above fix. Please review it and if it looks good, can you please commit the code.