message: Modify op version in optimize only if convertor version < quantized version.
diff: @@ -134,8 +134,10 @@ void SetOperatorCodeVersion(ModelT* model) {
  OperatorCodeT* op_code = model->operator_codes[op->opcode_index].get();
  operator_property::OperatorProperty property =
  operator_property::GetOperatorProperty(model, subgraph_idx, op_idx);
  - if (property.quantizable) {
  - // Only update the versions of quantizable operations.
  + if (property.quantizable && op_code->version < property.version) {
  + // Only update the versions of quantizable operations if the original
  + // version is lesser than minimum quantized one mentioned by
  + // OperatorProperty.
  op_code->version = property.version;
  }
  }
  