[status_manager] Fix listener statistics update

Octavia offers a dedicated ListenerStatistics class now, which is also
the model_class of self.listener_stats_repo

Also: Remove docstring for v1, v1 is not used.

octavia_f5/controller/statusmanager/legacy_healthmanager/health_drivers/update_db.py

@@ -484,38 +484,12 @@ def update_stats(self, health_message, srcaddr):
                           '%s', health_message['id'], srcaddr)
 
     def _update_stats(self, health_message, srcaddr):
-        """This function is to update the db with listener stats
+        """Update listener statistics
 
         :param health_message: The health message containing the listener stats
         :type map: string
         :returns: null
 
-        Example V1 message::
-
-            health = {
-                "id": self.FAKE_UUID_1,
-                "listeners": {
-                    "listener-id-1": {
-                        "status": constants.OPEN,
-                        "stats": {
-                            "ereq":0,
-                            "conns": 0,
-                            "totconns": 0,
-                            "rx": 0,
-                            "tx": 0,
-                        },
-                        "pools": {
-                            "pool-id-1": {
-                                "status": constants.UP,
-                                "members": {"member-id-1": constants.ONLINE}
-                            }
-                        }
-                    }
-                }
-            }
-
-        Example V2 message::
-
             {"id": "<amphora_id>",
              "seq": 67,
              "listeners": {
@@ -553,8 +527,11 @@ def _update_stats(self, health_message, srcaddr):
                      'active_connections': stats['conns'],
                      'total_connections': stats['totconns'],
                      'request_errors': stats['ereq']}
-            LOG.debug("Updating listener stats in db and sending event.")
+            stats_obj = self.listener_stats_repo.model_class(
+                listener_id=listener_id,
+                amphora_id=amphora_id,
+                **stats
+            )
             LOG.debug("Listener %s / Amphora %s stats: %s",
                       listener_id, amphora_id, stats)
-            self.listener_stats_repo.replace(
-                session, listener_id, amphora_id, **stats)
+            self.listener_stats_repo.replace(session, stats_obj)