message: [Grappler] Fix legacy V1 UT with Concat instead of ConcatV2
diff: @@ -1980,8 +1980,6 @@ class HoistCWiseUnaryChainsStage : public ArithmeticOptimizerStage {
  Status AddReshapeForConcate(
  NodeDef* reshape, NodeDef* concate_node, int port) {
  // Replace concate input with reshape
  - const int offset = concate_node->op() == "Concat" ? 1 : 0;
  - port += offset;
  const string concate_input = concate_node->input(port);
  if (reshape->name() == NodeName(concate_input)) {
  