message: Implement `InputDatasets` for AvroRecordDatasetOp
diff: @@ -56,6 +56,10 @@ class AvroRecordDatasetOp::Dataset : public DatasetBase {
  VLOG(7) << "Buffer size " << buffer_size / 1024 << "kBy";
  }
  + Status InputDatasets(std::vector<const DatasetBase*>* inputs) const {
  + return Status::OK();
  + }
  +
  std::unique_ptr<IteratorBase> MakeIteratorInternal(
  const string& prefix) const override {
  return absl::make_unique<Iterator>(Iterator::Params{
  