[TF] Workaround for  PRODX-7986

Due to the implementation specifics, in the case of TungstenFabric,
we need to request SG object to get the updated timestamp.

Related-PROD: PRODX-7986
Change-Id: Ieda423cf6d02a509d85846f968b1b2a90f04ee04
(cherry picked from commit 9c98912a9338d5d0b91c6b2510c6b5c56f9a745a)
(cherry picked from commit ce43690f444d75a81324120f639fcb0ce7e0f775)
(cherry picked from commit d1267dd167369e0ed02275c1575f2cdc73bc68b4)
diff --git a/neutron_tempest_plugin/api/test_timestamp.py b/neutron_tempest_plugin/api/test_timestamp.py
index c39c523..0cf28d5 100644
--- a/neutron_tempest_plugin/api/test_timestamp.py
+++ b/neutron_tempest_plugin/api/test_timestamp.py
@@ -15,7 +15,6 @@
 
 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
 
@@ -307,7 +306,7 @@
             security_group['id'], name=security_group['name'] + 'new')[
                 'security_group']
         # Workaround for PRODX-7986
-        if tempestconf.is_tungstenfabric_backend_enabled():
+        if CONF.service_available.contrail:
             updated_security_group = self.client.show_security_group(
                 security_group['id'])['security_group']