Make save_for_lite_interpreter private (#32771)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/32771
It's a patch to #32621, make the api private.
Test Plan: Imported from OSS
Differential Revision: D19657307
Pulled By: iseeyuan
fbshipit-source-id: e604a0cbed6a1e61413daaafc65bea92b90f1f5d
