Add type annotations to torch.overrides (#50824)
Summary:
This is a follow up PR of https://github.com/pytorch/pytorch/issues/48493.
Fixes https://github.com/pytorch/pytorch/issues/48492
Pull Request resolved: https://github.com/pytorch/pytorch/pull/50824
Reviewed By: bdhirsh
Differential Revision: D26050736
Pulled By: ezyang
fbshipit-source-id: 049605fd271cff28c8b6e300c163e9df3b3ea23b
