message: Fix flakiness of dataset_constructor_op_test and flat_map_dataset_op_test due to
  timeouts.
diff: @@ -88,7 +88,7 @@ py_test(
  py_test(
  name = "dataset_constructor_op_test",
  - size = "small",
  + size = "medium",
  srcs = ["dataset_constructor_op_test.py"],
  srcs_version = "PY2AND3",
  tags = [
  @@ -157,7 +157,7 @@ py_test(
  tf_py_test(
  name = "flat_map_dataset_op_test",
  - size = "small",
  + size = "medium",
  srcs = ["flat_map_dataset_op_test.py"],
  additional_deps = [
  ":dataset_serialization_test",
  