[neutron] Don't configure firewall_driver for core ML2 plugin

In the past firewall_driver setting was configured for ML2 plugin
because it was used in the
neutron.agent.securitygroups_rpc.is_firewall_enabled() function but
currently it's not needed anymore as there is other config option
"enable_security_group" for that.

Related-bug: #1996748
Change-Id: I9b09c6afb3f1f1c33d1bdfea52ba6f4c0d0cf2dc

Author: slawqo

lib/neutron_plugins/ml2

@@ -111,18 +111,7 @@ function neutron_plugin_configure_service {
             fi
         fi
     fi
-    # REVISIT(rkukura): Setting firewall_driver here for
-    # neutron.agent.securitygroups_rpc.is_firewall_enabled() which is
-    # used in the server, in case no L2 agent is configured on the
-    # server's node. If an L2 agent is configured, this will get
-    # overridden with the correct driver. The ml2 plugin should
-    # instead use its own config variable to indicate whether security
-    # groups is enabled, and that will need to be set here instead.
-    if [[ "$Q_USE_SECGROUP" == "True" ]]; then
-        iniset /$Q_PLUGIN_CONF_FILE securitygroup firewall_driver neutron.agent.not.a.real.FirewallDriver
-    else
-        iniset /$Q_PLUGIN_CONF_FILE securitygroup firewall_driver neutron.agent.firewall.NoopFirewallDriver
-    fi
+    populate_ml2_config /$Q_PLUGIN_CONF_FILE securitygroup enable_security_group=$Q_USE_SECGROUP
 
     populate_ml2_config /$Q_PLUGIN_CONF_FILE ml2 mechanism_drivers=$Q_ML2_PLUGIN_MECHANISM_DRIVERS
     if [[ "$Q_ML2_PLUGIN_MECHANISM_DRIVERS" == *"linuxbridge"* ]]; then