[services] Backup - Send Log - Use separate variables for value and blob holder

Summary:
Depends on D4321

We want to use separate variables for the blob hash and value instead of just one variable value

Test Plan: Services build, for now this went out of sync with the integration tests

Reviewers: palys-swm

Reviewed By: palys-swm

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

Differential Revision: https://phab.comm.dev/D4411