Skip stateless SG dualstack tests when openvswitch fw driver is used

Openvswitch firewall driver does not support stateless SG so tests from
classes:
StatelessSecGroupDualStackDHCPv6StatelessTest
StatelessSecGroupDualStackSlaacTest

from the module neutron_tempest_plugin.scenario.test_security_groups
should be skipped in such case.

Closes-bz: https://bugzilla.redhat.com/show_bug.cgi?id=2227138
Change-Id: Ice0f3573dd51851752c745c0b1d35c82bd7808fd
diff --git a/neutron_tempest_plugin/scenario/test_security_groups.py b/neutron_tempest_plugin/scenario/test_security_groups.py
index ed9ff8c..e2d25ee 100644
--- a/neutron_tempest_plugin/scenario/test_security_groups.py
+++ b/neutron_tempest_plugin/scenario/test_security_groups.py
@@ -1137,6 +1137,10 @@
             should_succeed=True)
 
 
+@testtools.skipIf(
+    CONF.neutron_plugin_options.firewall_driver in ['openvswitch', 'None'],
+    "Firewall driver other than 'openvswitch' is required to use "
+    "stateless security groups.")
 class StatelessSecGroupDualStackSlaacTest(BaseNetworkSecGroupTest):
     required_extensions = ['security-group', 'stateful-security-group']
     stateless_sg = True
@@ -1180,6 +1184,10 @@
         self._test_default_sec_grp_scenarios()
 
 
+@testtools.skipIf(
+    CONF.neutron_plugin_options.firewall_driver in ['openvswitch', 'None'],
+    "Firewall driver other than 'openvswitch' is required to use "
+    "stateless security groups.")
 class StatelessSecGroupDualStackDHCPv6StatelessTest(
         StatelessSecGroupDualStackSlaacTest):
     required_extensions = ['security-group', 'stateful-security-group']