message: Add compression mode as a hashing parameter for graph hashes
  Different compression modes result in different snapshots that are not mutually readable.
diff: @@ -821,6 +821,9 @@ void SnapshotDatasetV2Op::MakeDataset(OpKernelContext* ctx, DatasetBase* input,
  ctx, AsGraphDef(ctx, input, SerializationContext(params), &graph_def));
  OP_REQUIRES_OK(ctx, HashGraph(graph_def, &graph_hash));
  + // Different compression modes should result in different graph hashes.
  + graph_hash = Hash64Combine(graph_hash, Hash64(compression_));
  +
  std::unique_ptr<CapturedFunction> reader_func;
  OP_REQUIRES_OK(ctx,
  CapturedFunction::Create(ctx, reader_func_metadata_,
  