Update padding='SAME' in tf.image.ssim API
Hi @cantonios Can you please review this PR ? Thank you! Hi @SuryanarayanaY Can you please check @cantonios's [comments](https://github.com/tensorflow/tensorflow/pull/60251#pullrequestreview-1419096529) ? Thank you! Hi @SuryanarayanaY Any update on this PR? Please. Thank you! I need some information on which tests are failing.Shall we need to update the all the failed test cases ?  A test demo shall be appreciated.
 Are those tests listed here at i[mage_ops_test.py](https://github.com/tensorflow/tensorflow/blob/master/tensorflow/python/ops/image_ops_test.py) ? Hi @cantonios Can you please assist on above [comments](https://github.com/tensorflow/tensorflow/pull/60251#issuecomment-1582164124) from @SuryanarayanaY. Thank you! `//tensorflow/python:image_ops_test_cpu` fails, for example.  Pretty much every existing test that actually uses ssim.

Yes, all the tests need to be updated. Hi @SuryanarayanaY Any update on this PR? Please. Thank you!
 Hi @SuryanarayanaY Any update on this PR? Please. Thank you! Need some time to work on this.Thanks! This PR is stale because it has been open for 14 days with no activity. It will be closed if no further activity occurs. Thank you. This PR was closed because it has been inactive for 14 days since being marked as stale. Please reopen if you'd like to work on this further.
Currently the API `tf.image.ssim` is using `padding='VALID'` internally. But with this padding the shape of the output is not matching with what documentation states. With `return_index_map=True` the output shape should be `broadcast(img1.shape[:-1], img2.shape[:-1])`. 

But with` padding='VALID'`, for input of shape `(16, 2106, 80, 1)` the current output shape is `(16, 2096, 70)` which is not matching with the expected output which should be `(16, 2106, 80)`. With `padding='SAME'` the output is matching to the desired output. 

Please refer to the attached [gist](https://colab.research.google.com/gist/SuryanarayanaY/d75ef4fcbd69b5211975fd4d29490084/59067_r1.ipynb) showcasing all the mentioned details. 

Fixes #59067 