Unify check for TF backend

Related-Prod: PRODX-37464
Change-Id: I39e7ac4b28207f705b54d7a7204894510f2f1045
(cherry picked from commit 7e1a858d04a85ee5964bc98d926620a80afe0b46)
diff --git a/neutron_tempest_plugin/api/test_timestamp.py b/neutron_tempest_plugin/api/test_timestamp.py
index c3227a9..c39c523 100644
--- a/neutron_tempest_plugin/api/test_timestamp.py
+++ b/neutron_tempest_plugin/api/test_timestamp.py
@@ -15,6 +15,7 @@
 
 from neutron_lib import constants
 from tempest.common import utils
+from tempest import config as tempestconf
 from tempest.lib.common.utils import data_utils
 from tempest.lib import decorators
 
@@ -305,6 +306,10 @@
         updated_security_group = self.client.update_security_group(
             security_group['id'], name=security_group['name'] + 'new')[
                 'security_group']
+        # Workaround for PRODX-7986
+        if tempestconf.is_tungstenfabric_backend_enabled():
+            updated_security_group = self.client.show_security_group(
+                security_group['id'])['security_group']
 
         # Verify that created_at hasn't changed
         self.assertEqual(security_group['created_at'],