Api-ref: update volume type interface's response parameters are inconsistent

[Brin Zhang]

There are "qos_specs_id" and "os-volume-type-access:is_public" fields not in the response list, but are in the response example.

Current status:
Response Parameters
Name In Type Description
volume_type body object A volume_type object.
is_public body boolean Whether the volume type is publicly visible.
extra_specs (Optional) body object A key and value pair that contains additional specifications that are associated
                                with the volume type. Examples include capabilities, capacity, compression, and so on,
                                depending on the storage driver in use.
description body string The volume type description.
name body string The name of the volume type.
id path string The UUID for an existing volume type.

Response Example
{
    "volume_type": {
        "id": "6685584b-1eac-4da6-b5c3-555430cf68ff",
        "qos_specs_id": null,
        "name": "vol-type-001",
        "description": "volume type 001",
        "os-volume-type-access:is_public": true,
        "is_public": true,
        "extra_specs": {
            "capabilities": "gpu"
        }
    }
}

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/624865

[OpenStack Infra (hudson-openstack)]

Change abandoned by Brin Zhang (<email address hidden>) on branch: master
Review: https://review.openstack.org/624865
Reason: This not a bug, this response is from v2 api, not from v1 api, so abandon this.