Apply clang-format to rpc cpp files (#50236)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/50236
Test Plan: Imported from OSS
Reviewed By: lw
Differential Revision: D25847892
Pulled By: mrshenli
fbshipit-source-id: b4af1221acfcaba8903c629869943abbf877e04e
