Enable distributed autograd tests for >py36
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/27166
Test Plan: Imported from OSS
Reviewed By: zhaojuanmao
Differential Revision: D17694691
Pulled By: mrshenli
fbshipit-source-id: 6e7b740645891fd3cc67600de26346f7b336773b
