Update layout optimizer config code. pruning and constfold are enabled by default now (no need to explicitly specify them any more).
Update layout optimizer config code. pruning and constfold are enabled by default now (no need to explicitly specify them any more).

PiperOrigin-RevId: 175743440

tensorflow/tensor2tensor,vthorsteinsson/tensor2tensor,tensorflow/tensor2tensor,rsepassi/tensor2tensor,tensorflow/tensor2tensor,rsepassi/tensor2tensor,vthorsteinsson/tensor2tensor,tensorflow/tensor2tensor,vthorsteinsson/tensor2tensor,tensorflow/tensor2tensor,rsepassi/tensor2tensor,rsepassi/tensor2tensor,vthorsteinsson/tensor2tensor