fix missing attribute in telemetry ut

Author: jiapinw

tests/unit/sagemaker/serve/utils/test_telemetry_logger.py

@@ -162,6 +162,7 @@ def test_capture_telemetry_decorator_no_call_when_disabled(self, mock_send_telem
         mock_model_builder = ModelBuilderMock()
         mock_model_builder.serve_settings.telemetry_opt_out = True
         mock_model_builder.image_uri = MOCK_DJL_CONTAINER
+        mock_model_builder._is_custom_image_uri = False
         mock_model_builder.model = MOCK_HUGGINGFACE_ID
         mock_model_builder.model_server = ModelServer.DJL_SERVING