use callback payloads for AGENT OVS_RESTARTED events

This patch switches the code over to the payload style of callbacks [1]
for AGENT OVS_RESTARTED events. In addition it updates the unit tests to
also use payloads for OVS_RESTARTED based events as needed.

[1] https://docs.openstack.org/neutron-lib/latest/contributor/callbacks.html

Change-Id: I7b774735fb875a808b048a17da1e0487e5bbcb44

neutron/agent/linux/openvswitch_firewall/firewall.py

@@ -411,7 +411,7 @@ class OVSFirewallDriver(firewall.FirewallDriver):
             callbacks_resources.AGENT,
             callbacks_events.OVS_RESTARTED)
 
-    def _init_firewall_callback(self, resource, event, trigger, **kwargs):
+    def _init_firewall_callback(self, resource, event, trigger, payload=None):
         LOG.info("Reinitialize Openvswitch firewall after OVS restart.")
         self._initialize_firewall()
 

neutron/plugins/ml2/drivers/openvswitch/agent/ovs_neutron_agent.py

@@ -2123,10 +2123,10 @@ class OVSNeutronAgent(l2population_rpc.L2populationRpcCallBackTunnelMixin,
             self.dvr_agent.reset_dvr_parameters()
             self.dvr_agent.setup_dvr_flows()
         # notify that OVS has restarted
-        registry.notify(
+        registry.publish(
             callback_resources.AGENT,
             callback_events.OVS_RESTARTED,
-            self)
+            self, payload=None)
         # restart the polling manager so that it will signal as added
         # all the current ports
         # REVISIT (rossella_s) Define a method "reset" in

neutron/tests/functional/agent/test_l2_ovs_agent.py

@@ -341,7 +341,7 @@ class TestOVSAgent(base.OVSAgentTestFramework):
 
         callback.assert_called_with(resources.AGENT,
                                     events.OVS_RESTARTED,
-                                    mock.ANY)
+                                    mock.ANY, payload=None)
 
 
 class TestOVSAgentExtensionConfig(base.OVSAgentTestFramework):