[services] Backup - Send log - add generate holder
Summary:
Depends on D3648
Adding the generateHolder method - for now, it's mocked, but I think it's important to be aware that it should be implemented and this diff clearly indicates that.
Test Plan:
cd services yarn run-backup-service
Reviewers: palys-swm, geekbrother
Reviewed By: palys-swm
Subscribers: ashoat, palys-swm, Adrian, atul, benschac, yayabosh
Differential Revision: https://phabricator.ashoat.com/D3649