[pytorch] factor out binary size upload command (#40188)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/40188
Create a custom command for this task to avoid copy/paste for new build jobs.
Test Plan: Imported from OSS
Differential Revision: D22111114
Pulled By: ljk53
fbshipit-source-id: a7d4d6bbd61ba6b6cbaa137ec7f884736957dc39
