Switch to use stable data_utils

Tempest provides stable library interfaces under tempest.lib.
This patch switches to use it for data_utils.

Change-Id: Ia331ec10a84118e5d72a95f8f8b86509f57232a1
diff --git a/manila_tempest_tests/tests/scenario/manager.py b/manila_tempest_tests/tests/scenario/manager.py
index a1e6c6d..64c5e8a 100644
--- a/manila_tempest_tests/tests/scenario/manager.py
+++ b/manila_tempest_tests/tests/scenario/manager.py
@@ -24,12 +24,12 @@
 
 from tempest.common import compute
 from tempest.common import image as common_image
-from tempest.common.utils import data_utils
 from tempest.common.utils.linux import remote_client
 from tempest.common.utils import net_utils
 from tempest.common import waiters
 from tempest import config
 from tempest import exceptions
+from tempest.lib.common.utils import data_utils
 from tempest.lib.common.utils import test_utils
 from tempest.lib import exceptions as lib_exc
 import tempest.test