use qos rule type details api def from neutron-lib

The QoS rule type details extension's API definition was rehomed into
neutron-lib with I068fec43604b89dcc6e47c2793f8267c615144b4
This patch consumes it by using the API definition from lib and removing
the rehomed code.

NeutronLibImpact

Change-Id: I923f7313185a88a1b1b895d5407ec1c3f81d6533

neutron/extensions/qos_rule_type_details.py

@@ -13,61 +13,10 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from neutron_lib.api.definitions import qos as qos_apidef
+from neutron_lib.api.definitions import qos_rule_type_details as apidef
 from neutron_lib.api import extensions as api_extensions
 
 
-# The name of the extension.
-NAME = "Details of QoS rule types"
+class Qos_rule_type_details(api_extensions.APIExtensionDescriptor):
 
-# The alias of the extension.
-ALIAS = "qos-rule-type-details"
-
-# The description of the extension.
-DESCRIPTION = ("Expose details about QoS rule types supported by loaded "
-               "backend drivers")
-
-# The list of required extensions.
-REQUIRED_EXTENSIONS = [qos_apidef.ALIAS]
-
-# The list of optional extensions.
-OPTIONAL_EXTENSIONS = None
-
-# The resource attribute map for the extension.
-RESOURCE_ATTRIBUTE_MAP = {
-    qos_apidef.RULE_TYPES: {
-        'drivers': {'allow_post': False, 'allow_put': False,
-                    'is_visible': True}
-    }
-}
-
-
-class Qos_rule_type_details(api_extensions.ExtensionDescriptor):
-
-    @classmethod
-    def get_name(cls):
-        return NAME
-
-    @classmethod
-    def get_alias(cls):
-        return ALIAS
-
-    @classmethod
-    def get_description(cls):
-        return DESCRIPTION
-
-    @classmethod
-    def get_updated(cls):
-        return "2017-06-22T10:00:00-00:00"
-
-    def get_required_extensions(self):
-        return REQUIRED_EXTENSIONS or []
-
-    def get_optional_extensions(self):
-        return OPTIONAL_EXTENSIONS or []
-
-    def get_extended_resources(self, version):
-        if version == "2.0":
-            return RESOURCE_ATTRIBUTE_MAP
-        else:
-            return {}
+    api_definition = apidef