Disable network manager management on a list of network interfaces.

    Args:
      interfaces: list of string, the output device names enable.
      logger: logger object, used to write to SysLog and serial port.

def _DisableNetworkManager(self, interfaces, logger):
    """Disable network manager management on a list of network interfaces.

    Args:
      interfaces: list of string, the output device names enable.
      logger: logger object, used to write to SysLog and serial port.
    """
    for interface in interfaces:
      interface_config = os.path.join(
          self.network_path, 'ifcfg-%s' % interface)
      if os.path.exists(interface_config):
        self._ModifyInterface(
            interface_config, 'DEVICE', interface, replace=False)
        self._ModifyInterface(
            interface_config, 'NM_CONTROLLED', 'no', replace=True)
      else:
        with open(interface_config, 'w') as interface_file:
          interface_content = [
              '# Added by Google.',
              'BOOTPROTO=none',
              'DEFROUTE=no',
              'DEVICE=%s' % interface,
              'IPV6INIT=no',
              'NM_CONTROLLED=no',
              'NOZEROCONF=yes',
              '',
          ]
          interface_file.write('\n'.join(interface_content))
        logger.info('Created config file for interface %s.', interface)