Various cleanups to pytorch_android API (#27454)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/27454
See detailed discussion at
https://github.com/pytorch/pytorch/issues/27350
Test Plan: Imported from OSS
Reviewed By: IvanKobzarev
Differential Revision: D17800480
Pulled By: dreiss
fbshipit-source-id: bf174e8b16231b89be771de0fa54c41e864a3eb0
