Return a 404 on ResourceNotFoundException Current implementation returns a 500, which is incorrect. A ResourceNotFoundException indicates a resource could not be found, which is REST translates to a 404 http code. Returning a 404 will ensure that clients will be able to correctly identify missing projects. Bug: Issue 16730 Change-Id: Ifb331dcee7165b7b2f2b33879c6c3cd2edfe8cc2