Share one PadRemover across all Transformer encoder layers
Share one PadRemover across all Transformer encoder layers

PiperOrigin-RevId: 167791186

tensorflow/tensor2tensor,vthorsteinsson/tensor2tensor,rsepassi/tensor2tensor,rsepassi/tensor2tensor,rsepassi/tensor2tensor,rsepassi/tensor2tensor,tensorflow/tensor2tensor,vthorsteinsson/tensor2tensor,vthorsteinsson/tensor2tensor,waterblue13/tensor2tensor,tensorflow/tensor2tensor,tensorflow/tensor2tensor,waterblue13/tensor2tensor,vthorsteinsson/tensor2tensor,tensorflow/tensor2tensor,waterblue13/tensor2tensor