message: [tf.data service] Modify the test so the dataset is distributed.
diff: @@ -433,7 +433,7 @@ class DataServiceOpsTest(data_service_test_base.TestBase,
  def interleave_fn(_):
  dataset = dataset_ops.Dataset.range(2)
  - self.make_distributed_dataset(dataset, cluster)
  + dataset = self.make_distributed_dataset(dataset, cluster)
  return dataset
  ds = ds.interleave(interleave_fn, cycle_length=2)
  