Output UnionType str rep with () instead of [] (#69502)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/69502
Test Plan: Imported from OSS
Reviewed By: pbelevich
Differential Revision: D32902781
Pulled By: tugsbayasgalan
fbshipit-source-id: 67a73b209575437477cdbd3eb8f685019709e99c
