[services] Backup - fix formatting

Summary: For some reason formatter didn't work. My suspicion was that it was my fault as I switched to the m1 and didn't see that the hooks don't run.

Test Plan: just formatting, services build as usual

Reviewers: palys-swm

Reviewed By: palys-swm

Subscribers: ashoat, Adrian, atul, yayabosh

Differential Revision: https://phab.comm.dev/D4549