Simplify calls to embedding_to_padding, we always end up converting the padding mask to a float tensor.
Simplify calls to embedding_to_padding, we always end up converting the padding mask to a float tensor.

PiperOrigin-RevId: 164777753

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