[services] Backup - Fix CI

Summary:
This fixes the CI that was broken because of mistakenly landed diffs for the new backup version.
First, we have to finish the arch design D2950
Then we need to update proto files D3076

Until these two diffs are not landed, we may land this quick fix just to unblock the CI

Test Plan:

cd services
yarn run-backup-service

Reviewers: palys-swm, ashoat, geekbrother

Reviewed By: palys-swm, ashoat

Subscribers: benschac, ashoat, palys-swm, Adrian, atul

Differential Revision: https://phabricator.ashoat.com/D3146