add _save_parameters to serialize map (#43163)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/43163
Test Plan: Imported from OSS
Reviewed By: iseeyuan
Differential Revision: D23175287
Pulled By: ann-ss
fbshipit-source-id: ddfd734513c07e8bdbec108f26d1ca1770d098a6
