Enables non-default CUDA stream in test_nn (#28192)
Summary:
Per title. Several stream fixes have gone in that may make this pass in CI.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/28192
Differential Revision: D17974219
Pulled By: mruberry
fbshipit-source-id: 543d000789c83711a8b4bef169a87635fda7508b
