CertificateValidationTest needs subnet

Change-Id: I762fb74b84b4eac3ec20f8a972fa18171b0cc65e
Related-Prod: PRODX-25589
Related-Prod: PRODX-25902
diff --git a/barbican_tempest_plugin/tests/scenario/test_certificate_validation.py b/barbican_tempest_plugin/tests/scenario/test_certificate_validation.py
index 60f60a9..cea6ef3 100644
--- a/barbican_tempest_plugin/tests/scenario/test_certificate_validation.py
+++ b/barbican_tempest_plugin/tests/scenario/test_certificate_validation.py
@@ -32,7 +32,7 @@
 
     @classmethod
     def setup_credentials(cls):
-        cls.set_network_resources(network=True)
+        cls.set_network_resources(network=True, subnet=True)
         super().setup_credentials()
 
     @classmethod