'Proxy an RPC message as-is to a manager.'

@oslo_messaging.expected_exceptions(exception.CellRoutingInconsistency)
def proxy_rpc_to_manager(self, ctxt, topic, rpc_message, call, timeout):

    compute_topic = compute_rpcapi.RPC_TOPIC
    cell_and_host = topic[(len(compute_topic) + 1):]
    (cell_name, host_name) = cells_utils.split_cell_and_item(cell_and_host)
    response = self.msg_runner.proxy_rpc_to_manager(ctxt, cell_name, host_name, topic, rpc_message, call, timeout)
    return response.value_or_raise()
