Fix tests

* replace service to systemctl call for sync time
* Add forward policy accept after docker install
due to https://github.com/moby/moby/pull/28257 break gtw node

Change-Id: I790bc9c1b2f203119d4142ec25956634bf6bb94f
diff --git a/tcp_tests/managers/openstack_manager.py b/tcp_tests/managers/openstack_manager.py
index bbf9315..275ef57 100644
--- a/tcp_tests/managers/openstack_manager.py
+++ b/tcp_tests/managers/openstack_manager.py
@@ -105,6 +105,10 @@
         with self.__underlay.remote(node_name=target_name[0]) as node_remote:
             result = node_remote.execute(cmd, verbose=True)
 
+        cmd_iptables = "iptables --policy FORWARD ACCEPT"
+        with self.__underlay.remote(node_name=target_name[0]) as node_remote:
+            result = node_remote.execute(cmd_iptables, verbose=True)
+
         with self.__underlay.remote(
                 host=self.__config.salt.salt_master_host) as node_remote:
             result = node_remote.execute(