Overload TestCase not vanilla TestCase for some elastic tests (#67700)
Summary:
Addresses a bit of https://github.com/pytorch/pytorch/issues/66903
Fixes it so that https://github.com/pytorch/pytorch/issues/66207 can be properly disabled
cc pietern mrshenli pritamdamania87 zhaojuanmao satgera rohan-varma gqchen aazzolini osalpekar jiayisuse SciPioneer H-Huang
Pull Request resolved: https://github.com/pytorch/pytorch/pull/67700
Reviewed By: H-Huang
Differential Revision: D32116908
Pulled By: janeyx99
fbshipit-source-id: 205ff68a7408609cfced2357fd99f41949ef6390
