Skip test_create_server_from_snapshot with image signing

native tempest tests are not written with handling
of image signing enforcement in mind.

Closes-Issue: PRODX-37479
Change-Id: I65cd217830b1848d80605edf90e81e8a05391e6a
(cherry picked from commit a58e9ef9e5e6cdd5d9ba4659e23e8645636f714d)
diff --git a/tempest/api/compute/images/test_images.py b/tempest/api/compute/images/test_images.py
index 87cedae..ff0d458 100644
--- a/tempest/api/compute/images/test_images.py
+++ b/tempest/api/compute/images/test_images.py
@@ -133,6 +133,9 @@
         self.addCleanup(self.client.delete_image, image['id'])
         self.assertEqual(snapshot_name, image['name'])
 
+    @testtools.skipIf(
+        CONF.compute_feature_enabled.barbican_integration_enabled,
+        "Not supported when barbican integration enabled.")
     @decorators.idempotent_id('f3cac456-e3fe-4183-a7a7-a59f7f017088')
     def test_create_server_from_snapshot(self):
         # Create one server normally