Only run _save_first_checkpoint if config.is_chief in keras.model_to_estimator to prevent races between workers trying to write to the same checkpoint filepath.
Only run _save_first_checkpoint if config.is_chief in keras.model_to_estimator to prevent races between workers trying to write to the same checkpoint filepath.

PiperOrigin-RevId: 317928337

tensorflow/estimator,tensorflow/estimator