message: wasm: add missed serialization failures.
diff: @@ -1044,10 +1044,10 @@ WasmResult serializeValue(Filters::Common::Expr::CelValue value, std::string* re
  using Filters::Common::Expr::CelValue;
  switch (value.type()) {
  case CelValue::Type::kMessage:
  - if (value.MessageOrDie() != nullptr) {
  - value.MessageOrDie()->SerializeToString(result);
  + if (value.MessageOrDie() != nullptr && value.MessageOrDie()->SerializeToString(result)) {
  return WasmResult::Ok;
  }
  + return WasmResult::SerializationFailure;
  case CelValue::Type::kString:
  result->assign(value.StringOrDie().value().data(), value.StringOrDie().value().size());
  return WasmResult::Ok;
  