Add the docstring for tf.keras.optimizers.serialize()
Add the docstring for tf.keras.optimizers.serialize()

PiperOrigin-RevId: 363757552
Change-Id: Ib6053e90f53d771bad395f54c622ca5675f0d7cc

petewarden/tensorflow,frreiss/tensorflow-fred,yongtang/tensorflow,petewarden/tensorflow,Intel-tensorflow/tensorflow,Intel-Corporation/tensorflow,frreiss/tensorflow-fred,tensorflow/tensorflow,frreiss/tensorflow-fred,tensorflow/tensorflow-pywrap_tf_optimizer,tensorflow/tensorflow-experimental_link_static_libraries_once,sarvex/tensorflow,paolodedios/tensorflow,Intel-tensorflow/tensorflow,karllessard/tensorflow,gautam1858/tensorflow,yongtang/tensorflow,sarvex/tensorflow,petewarden/tensorflow,tensorflow/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,tensorflow/tensorflow-pywrap_saved_model,Intel-tensorflow/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,karllessard/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,tensorflow/tensorflow-pywrap_saved_model,paolodedios/tensorflow,Intel-Corporation/tensorflow,karllessard/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow-experimental_link_static_libraries_once,tensorflow/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,paolodedios/tensorflow,karllessard/tensorflow,petewarden/tensorflow,karllessard/tensorflow,gautam1858/tensorflow,sarvex/tensorflow,Intel-tensorflow/tensorflow,gautam1858/tensorflow,tensorflow/tensorflow,Intel-tensorflow/tensorflow,frreiss/tensorflow-fred,Intel-tensorflow/tensorflow,Intel-Corporation/tensorflow,tensorflow/tensorflow-pywrap_saved_model,karllessard/tensorflow,yongtang/tensorflow,karllessard/tensorflow,petewarden/tensorflow,tensorflow/tensorflow-pywrap_saved_model,petewarden/tensorflow,yongtang/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,paolodedios/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,tensorflow/tensorflow-pywrap_tf_optimizer,frreiss/tensorflow-fred,tensorflow/tensorflow-experimental_link_static_libraries_once,paolodedios/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,tensorflow/tensorflow-pywrap_tf_optimizer,frreiss/tensorflow-fred,tensorflow/tensorflow,tensorflow/tensorflow,petewarden/tensorflow,yongtang/tensorflow,paolodedios/tensorflow,Intel-tensorflow/tensorflow,Intel-Corporation/tensorflow,Intel-Corporation/tensorflow,petewarden/tensorflow,frreiss/tensorflow-fred,karllessard/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,Intel-Corporation/tensorflow,sarvex/tensorflow,paolodedios/tensorflow,Intel-Corporation/tensorflow,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow-pywrap_tf_optimizer,paolodedios/tensorflow,sarvex/tensorflow,tensorflow/tensorflow,gautam1858/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,tensorflow/tensorflow-pywrap_saved_model,petewarden/tensorflow,yongtang/tensorflow,yongtang/tensorflow,yongtang/tensorflow,tensorflow/tensorflow,Intel-tensorflow/tensorflow,gautam1858/tensorflow,gautam1858/tensorflow,paolodedios/tensorflow,gautam1858/tensorflow,Intel-Corporation/tensorflow,karllessard/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,gautam1858/tensorflow,frreiss/tensorflow-fred,tensorflow/tensorflow,gautam1858/tensorflow,paolodedios/tensorflow,karllessard/tensorflow,frreiss/tensorflow-fred,tensorflow/tensorflow-pywrap_saved_model,Intel-tensorflow/tensorflow,gautam1858/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,gautam1858/tensorflow,tensorflow/tensorflow,yongtang/tensorflow,petewarden/tensorflow,yongtang/tensorflow,petewarden/tensorflow,sarvex/tensorflow,frreiss/tensorflow-fred,paolodedios/tensorflow,Intel-tensorflow/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow-pywrap_saved_model,sarvex/tensorflow,Intel-tensorflow/tensorflow,sarvex/tensorflow,frreiss/tensorflow-fred,tensorflow/tensorflow-pywrap_tf_optimizer,frreiss/tensorflow-fred,yongtang/tensorflow,gautam1858/tensorflow,karllessard/tensorflow,petewarden/tensorflow,tensorflow/tensorflow,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow-experimental_link_static_libraries_once