GaussianNLLLoss no_batch_dim docs and testing (#69783)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/69783
Test Plan: Imported from OSS
Reviewed By: jbschlosser
Differential Revision: D33200486
Pulled By: george-qi
fbshipit-source-id: a2bc2b366772682825f879dae4ac29c1f4d6a5f1
