Change `dim` to `axis` for cosine_distance (#12801)

* Change `dim` to `axis` for cosine_distance

This fix changes  `dim` to `axis` for cosine_distance
so that the args are consistent with other methods in TensorFlow.

The backward-compatibility has been maintained in the fix.

This fix fixes 8205.

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

* Change `dim` to `axis` for tf.losses.cosine_distance

so that args are consistent with other TensorFlow methods.

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

* Update API goldens and address review feedback

This commit updates API goldens so that
`//tensorflow/tools/api/tests:api_compatibility_test`
could pass. Review feedback has also been addressed.

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>