This change updates the spec to reflect the actual implementation.
* The neutron_port_id field is vif_id
The Neutron port ID is stored in vif_id, not neutron_port_id.
* The neutron_network_id field is network_id
The Neutron network ID is stored in network_id, not neutron_network_id.
* The network_id and vif_id values are lower case
Actual values passed in implementation are lower case. Update example
so one does not conclude that Nova explicitly upper case the values.
Change-Id: Ie84013771649d336c3b7e72c1e8c4f2073116b16
b22bc8a2db