Assign variant_tensor_name by value in AddDeserializationOpsForParame…

…ters.

The reference is invalidated by the line:
binding.mutable_sequence()->Clear()
so its use on the subsequent line causes errors. Making variant_tensor_name not a reference fixes this.

PiperOrigin-RevId: 402698870

tensorflow_federated/cc/core/impl/executors/tensorflow_executor.cc

@@ -146,7 +146,7 @@ absl::Status AddDeserializationOpsForParameters(
  case v0::TensorFlow::Binding::kSequence: {
  // Get the name of the placeholder we're operating on and create a name
  // for the new deserialization op.
- const std::string& variant_tensor_name =
+ const std::string variant_tensor_name =
  binding.sequence().variant_tensor_name();
  auto graph_names = GetVariantTensorNodeNameAndReplacement(
  variant_tensor_name, kDatasetFromGraphOp, prefix);