[FSDP] Fix for optim state dict (#102901)
Fix for HSDP + use_orig_params where we need to pass in the PG that
might not be the default.
Differential Revision: [D46417327](https://our.internmc.facebook.com/intern/diff/D46417327/)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/102901
Approved by: https://github.com/wz337
