Add neutron-tempest-plugin-scenario-ovn jobs

Change-Id: I4818786988a22d941a1de348d3beb5159baaa48c
diff --git a/zuul.d/ussuri_jobs.yaml b/zuul.d/ussuri_jobs.yaml
index 4e7bd5d..d88b165 100644
--- a/zuul.d/ussuri_jobs.yaml
+++ b/zuul.d/ussuri_jobs.yaml
@@ -115,6 +115,16 @@
         NETWORK_API_EXTENSIONS: "{{ network_api_extensions | join(',') }}"
 
 - job:
+    name: neutron-tempest-plugin-scenario-ovn-ussuri
+    parent: neutron-tempest-plugin-scenario-ovn
+    override-checkout: stable/ussuri
+    vars:
+      branch_override: stable/ussuri
+      network_api_extensions: *api_extensions
+      devstack_localrc:
+        NETWORK_API_EXTENSIONS: "{{ network_api_extensions | join(',') }}"
+
+- job:
     name: neutron-tempest-plugin-dvr-multinode-scenario-ussuri
     parent: neutron-tempest-plugin-dvr-multinode-scenario
     override-checkout: stable/ussuri