[services] Rust Integration - Backup - c++ - Fix wrong order of attachment holders in tests

Summary:
Depends on D5073

This addresses a similar problem to the one shown in D5072. This time it refers to the attachment holders for logs.

Test Plan: services build and all tests pass (integration, performance).

Reviewers: jon, max, varun, tomek

Reviewed By: jon, tomek

Subscribers: ashoat, tomek, atul, abosh

Differential Revision: https://phab.comm.dev/D5074