Fix deprecation message from GatherV2Grad
Fix deprecation message from GatherV2Grad

This PR tries to fix the issue in 39701 where there are deprecation message from GatherV2Grad:
```
WARNING:tensorflow:From /usr/local/lib/python3.7/site-packages/tensorflow/python/ops/array_grad.py:644: _EagerTensorBase.cpu (from tensorflow.python.framework.ops) is deprecated and will be removed in a future version.
Instructions for updating:
Use tf.identity instead.
```

This PR fixes the message and use array_ops.identity instead (as was suggested by message).

This PR fixes 39701.

Signed-off-by: Yong Tang <765086fe2e0c1f980161f127fec596800f327f62@outlook.com>

aam-at/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,tensorflow/tensorflow-experimental_link_static_libraries_once,gautam1858/tensorflow,yongtang/tensorflow,karllessard/tensorflow,cxxgtxy/tensorflow,tensorflow/tensorflow,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow-experimental_link_static_libraries_once,tensorflow/tensorflow-pywrap_saved_model,paolodedios/tensorflow,aam-at/tensorflow,aam-at/tensorflow,tensorflow/tensorflow-pywrap_saved_model,frreiss/tensorflow-fred,petewarden/tensorflow,yongtang/tensorflow,tensorflow/tensorflow-pywrap_saved_model,yongtang/tensorflow,petewarden/tensorflow,frreiss/tensorflow-fred,paolodedios/tensorflow,davidzchen/tensorflow,paolodedios/tensorflow,annarev/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,sarvex/tensorflow,annarev/tensorflow,tensorflow/tensorflow-pywrap_saved_model,davidzchen/tensorflow,aldian/tensorflow,yongtang/tensorflow,petewarden/tensorflow,Intel-tensorflow/tensorflow,Intel-tensorflow/tensorflow,freedomtan/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,aam-at/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,Intel-tensorflow/tensorflow,gautam1858/tensorflow,yongtang/tensorflow,frreiss/tensorflow-fred,aam-at/tensorflow,aldian/tensorflow,paolodedios/tensorflow,davidzchen/tensorflow,tensorflow/tensorflow,paolodedios/tensorflow,sarvex/tensorflow,davidzchen/tensorflow,yongtang/tensorflow,annarev/tensorflow,freedomtan/tensorflow,Intel-Corporation/tensorflow,petewarden/tensorflow,tensorflow/tensorflow-pywrap_saved_model,sarvex/tensorflow,frreiss/tensorflow-fred,freedomtan/tensorflow,tensorflow/tensorflow,aldian/tensorflow,karllessard/tensorflow,tensorflow/tensorflow,petewarden/tensorflow,karllessard/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,petewarden/tensorflow,petewarden/tensorflow,annarev/tensorflow,freedomtan/tensorflow,paolodedios/tensorflow,gautam1858/tensorflow,paolodedios/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,yongtang/tensorflow,gautam1858/tensorflow,gautam1858/tensorflow,frreiss/tensorflow-fred,gautam1858/tensorflow,paolodedios/tensorflow,petewarden/tensorflow,Intel-tensorflow/tensorflow,frreiss/tensorflow-fred,cxxgtxy/tensorflow,tensorflow/tensorflow-pywrap_saved_model,petewarden/tensorflow,tensorflow/tensorflow,cxxgtxy/tensorflow,tensorflow/tensorflow,gautam1858/tensorflow,annarev/tensorflow,freedomtan/tensorflow,freedomtan/tensorflow,Intel-tensorflow/tensorflow,freedomtan/tensorflow,cxxgtxy/tensorflow,freedomtan/tensorflow,Intel-tensorflow/tensorflow,davidzchen/tensorflow,aldian/tensorflow,tensorflow/tensorflow,karllessard/tensorflow,Intel-tensorflow/tensorflow,aam-at/tensorflow,tensorflow/tensorflow,tensorflow/tensorflow,paolodedios/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,aldian/tensorflow,tensorflow/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,paolodedios/tensorflow,aam-at/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,petewarden/tensorflow,Intel-Corporation/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,tensorflow/tensorflow-pywrap_saved_model,frreiss/tensorflow-fred,davidzchen/tensorflow,sarvex/tensorflow,davidzchen/tensorflow,annarev/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,aam-at/tensorflow,cxxgtxy/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,Intel-tensorflow/tensorflow,gautam1858/tensorflow,freedomtan/tensorflow,davidzchen/tensorflow,Intel-Corporation/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,annarev/tensorflow,Intel-Corporation/tensorflow,davidzchen/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,tensorflow/tensorflow-experimental_link_static_libraries_once,cxxgtxy/tensorflow,aam-at/tensorflow,freedomtan/tensorflow,frreiss/tensorflow-fred,tensorflow/tensorflow-pywrap_saved_model,frreiss/tensorflow-fred,Intel-Corporation/tensorflow,gautam1858/tensorflow,aam-at/tensorflow,yongtang/tensorflow,aldian/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,karllessard/tensorflow,gautam1858/tensorflow,annarev/tensorflow,davidzchen/tensorflow,sarvex/tensorflow,davidzchen/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,karllessard/tensorflow,gautam1858/tensorflow,sarvex/tensorflow,aam-at/tensorflow,yongtang/tensorflow,aam-at/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,Intel-tensorflow/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,frreiss/tensorflow-fred,karllessard/tensorflow,karllessard/tensorflow,davidzchen/tensorflow,petewarden/tensorflow,petewarden/tensorflow,Intel-tensorflow/tensorflow,paolodedios/tensorflow,Intel-Corporation/tensorflow,freedomtan/tensorflow,aldian/tensorflow,aldian/tensorflow,Intel-Corporation/tensorflow,Intel-Corporation/tensorflow,yongtang/tensorflow,tensorflow/tensorflow-pywrap_saved_model,karllessard/tensorflow,karllessard/tensorflow,Intel-tensorflow/tensorflow,karllessard/tensorflow,cxxgtxy/tensorflow,tensorflow/tensorflow-pywrap_saved_model,frreiss/tensorflow-fred,annarev/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,sarvex/tensorflow,freedomtan/tensorflow,frreiss/tensorflow-fred,annarev/tensorflow,gautam1858/tensorflow,sarvex/tensorflow,tensorflow/tensorflow,annarev/tensorflow,cxxgtxy/tensorflow,yongtang/tensorflow