R4.1 : Automation: disable_policy test code in port_fix does not work, need to be fixed

The following code to enable/disable policy does not work, need to be fixed.

    def disable_policy(self):
        return self.set_policy(self, False)

    def enable_policy(self):
        return self.set_policy(self, True)

    def set_policy(self, value):
        vmi_obj = self.vnc_h.virtual_machine_interface_read(self.uuid)
        vmi_obj.set_virtual_machine_interface_disable_policy(bool(value))
        self.vnc_h.virtual_machine_interface_update(vmi_obj)