Update the keras version used by tensorflow for 2.7 release.
Update the keras version used by tensorflow for 2.7 release.

The keras 2.7 has been released at https://pypi.org/project/keras/2.7.0/

PiperOrigin-RevId: 407371581
Change-Id: If5e767ddf90addb5e4007f6d40c9b200f08230ae

yongtang/tensorflow,tensorflow/tensorflow,tensorflow/tensorflow,tensorflow/tensorflow-pywrap_saved_model,Intel-tensorflow/tensorflow,tensorflow/tensorflow-pywrap_saved_model,gautam1858/tensorflow,karllessard/tensorflow,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow-experimental_link_static_libraries_once,Intel-tensorflow/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,yongtang/tensorflow,paolodedios/tensorflow,tensorflow/tensorflow,tensorflow/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,gautam1858/tensorflow,karllessard/tensorflow,Intel-tensorflow/tensorflow,karllessard/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,paolodedios/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,paolodedios/tensorflow,Intel-Corporation/tensorflow,yongtang/tensorflow,Intel-Corporation/tensorflow,tensorflow/tensorflow-pywrap_saved_model,karllessard/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,gautam1858/tensorflow,paolodedios/tensorflow,Intel-tensorflow/tensorflow,tensorflow/tensorflow,yongtang/tensorflow,Intel-Corporation/tensorflow,yongtang/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,tensorflow/tensorflow-pywrap_tf_optimizer,tensorflow/tensorflow-pywrap_tf_optimizer,paolodedios/tensorflow,karllessard/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,karllessard/tensorflow,gautam1858/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,paolodedios/tensorflow,paolodedios/tensorflow,gautam1858/tensorflow,paolodedios/tensorflow,tensorflow/tensorflow-pywrap_saved_model,gautam1858/tensorflow,yongtang/tensorflow,Intel-tensorflow/tensorflow,Intel-tensorflow/tensorflow,karllessard/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,yongtang/tensorflow,yongtang/tensorflow,Intel-Corporation/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,tensorflow/tensorflow-experimental_link_static_libraries_once,tensorflow/tensorflow-experimental_link_static_libraries_once,karllessard/tensorflow,Intel-Corporation/tensorflow,gautam1858/tensorflow,karllessard/tensorflow,gautam1858/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,tensorflow/tensorflow-pywrap_saved_model,Intel-Corporation/tensorflow,yongtang/tensorflow,tensorflow/tensorflow-pywrap_saved_model,gautam1858/tensorflow,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow,yongtang/tensorflow,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,gautam1858/tensorflow,tensorflow/tensorflow,Intel-Corporation/tensorflow,Intel-tensorflow/tensorflow,tensorflow/tensorflow,Intel-tensorflow/tensorflow,paolodedios/tensorflow,gautam1858/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,gautam1858/tensorflow,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow,Intel-tensorflow/tensorflow,Intel-Corporation/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,karllessard/tensorflow,tensorflow/tensorflow,Intel-tensorflow/tensorflow,paolodedios/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow-pywrap_tf_optimizer,karllessard/tensorflow,paolodedios/tensorflow,yongtang/tensorflow,Intel-tensorflow/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once