Some xml tags are missed from edit-config body

[hrk091]

I've tried to compile OpenConfig model and to install sample config( not include IdentityRef ) to openconfig emulator via DynamicDeviceConfigSynchronizer. The config sample is

{
    "openconfig-system:system": {
        "clock": {
            "config": {
                "timezone-name": "UST"
            }
        }
    }
}

I successfully wrote the config to Dynamic Config Store without error, but OpenConfig emulator returned rpc-error like

<rpc-reply message-id="3" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  <rpc-error>
    <error-type>application</error-type>
    <error-tag>unknown-element</error-tag>
    <error-severity>error</error-severity>
    <error-path>
      /rpc/edit-config/config/oc-sys:clock
    </error-path>
    <error-info>
      <bad-element>clock</bad-element>
    </error-info>
  </rpc-error>
</rpc-reply>

The edit-config msg sent from netconf-driver may cause this error. I expect to DCS and netconf-driver to send edit-config msg as below

<rpc message-id="5" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  <edit-config xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0">
    <target>
      <running/>
    </target>
    <config>
      <system xmlns="http://openconfig.net/yang/system">
        <clock>
          <config>
            <timezone-name>UTC</timezone-name>
          </config>
        </clock>
      </system>
    </config>
  </edit-config>
</rpc>

but the onos netconf-driver sent these edit-config msgs according to a netconf trace log in emulator:

<rpc message-id="2" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  <edit-config>
    <target>
      <running/>
    </target>
    <config xmlns:xc="urn:ietf:params:xml:ns:netconf:base:1.0"/>
  </edit-config>
</rpc>

<rpc message-id="3" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  <edit-config>
    <target>
      <running/>
    </target>
    <config xmlns:xc="urn:ietf:params:xml:ns:netconf:base:1.0">
      <clock xmlns="http://openconfig.net/yang/system">
        <config>  
          <timezone-name>
            UTC
          </timezone-name>
        </config>
      </clock>
    </config>
  </edit-config>
</rpc>

<rpc message-id="4" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  <edit-config>
    <target>
      <running/>
    </target>
    <config xmlns:xc="urn:ietf:params:xml:ns:netconf:base:1.0">
      <config xmlns="http://openconfig.net/yang/system">
        <timezone-name>UTC</timezone-name>
      </config>
    </config>
  </edit-config>
</rpc>

<rpc message-id="5" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  <edit-config>
    <target>
      <running/>
    </target>
    <config xmlns:xc="urn:ietf:params:xml:ns:netconf:base:1.0">
      <timezone-name xmlns="http://openconfig.net/yang/system">UTC</timezone-name>
    </config>
  </edit-config>
</rpc>

<rpc message-id="6" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  <edit-config>
    <target>
      <running/>
    </target>
    <config xmlns:xc="urn:ietf:params:xml:ns:netconf:base:1.0"/>
  </edit-config>
</rpc>

All of these edit-configs caused rpc-error reply.
Sample app code is below

       DefaultSystem system = new DefaultSystem();

        DefaultClock clock = new DefaultClock();
        system.clock(clock);

        DefaultConfig config = new DefaultConfig();
        clock.config(config);

        TimezoneNameType timezone = new TimezoneNameType("UTC");
        config.timezoneName(timezone);

        ModelObjectData modelData = DefaultModelObjectData.builder()
                    .addModelObject(system)
                    .identifier(null)
                    .build();

In edit-config of message-id="3" above, system tag for system container is not written in config body. If the system tag is included, the rpc message will be accepted.