Merge "Cert: Use AdbProxy.tcp_forward() instead of raw forward command"

        :param device_port: device port, int

        :return: host port int

        """

        error_or_port = self.adb.forward(

            "tcp:%d tcp:%d" % (host_port, device_port), ignore_status=True)

        error_or_port = self.adb.tcp_forward(host_port, device_port)

        if not error_or_port:

            logging.debug("host port %d was already forwarded" % host_port)

            return host_port