CBQE-7125: Add import for RemoteUtilHelper

There are tests that rely on RemoteUtilHelper, which is not imported in
mad-hatter, causing failures.

Change-Id: I362fc388a57f064aaaf9e2ff66cbd43f4288cb2c
Reviewed-on: http://review.couchbase.org/c/testrunner/+/157599
Tested-by: Joe Mitchell Jones <joe.mitchelljones@couchbase.com>
Reviewed-by: Thuan Nguyen <soccon@gmail.com>

pytests/ent_backup_restore/enterprise_backup_restore_base.py

@@ -15,7 +15,7 @@
                                                  import BackupRestoreValidations
 from membase.helper.bucket_helper import BucketOperationHelper
 from membase.helper.cluster_helper import ClusterOperationHelper
-from remote.remote_util import RemoteMachineShellConnection
+from remote.remote_util import RemoteMachineShellConnection, RemoteUtilHelper
 from membase.api.rest_client import RestHelper, RestConnection, \
                                     Bucket as CBBucket
 from couchbase_helper.document import View