message: Allow passing custom image preprocessing config to the TFL eval tool.
diff: @@ -67,12 +67,16 @@ TfLiteStatus ImageClassificationStage::Init(
  }
  // ImagePreprocessingStage
  + if (!config_.specification().has_image_preprocessing_params()) {
  tflite::evaluation::ImagePreprocessingConfigBuilder builder(
  "image_preprocessing", input_type);
  builder.AddCroppingStep(kCroppingFraction, true /*square*/);
  builder.AddResizingStep(input_shape->data[2], input_shape->data[1], false);
  builder.AddDefaultNormalizationStep();
  preprocessing_stage_.reset(new ImagePreprocessingStage(builder.build()));
  + } else {
  + preprocessing_stage_.reset(new ImagePreprocessingStage(config_));
  + }
  if (preprocessing_stage_->Init() != kTfLiteOk) return kTfLiteError;
  // TopkAccuracyEvalStage.
  