Adds some more verbosity to gsutil rsync

What does this MR do?

For gitlab-com/gl-infra/production#8162 (comment 1226362124)

We see that our jobs are attempting a sync to GCS for auto-deploy tagged builds, but something is not working since no packages are showing up in the bucket. Example https://dev.gitlab.org/gitlab/omnibus-gitlab/-/jobs/14747423

This change adds a bit more verbosity by not using the quiet option for gsutil, and also reporting the exit code of the two system commands.

I've done a sanity check using the same image and the same key and sync appears to be working fine, so I'm not sure why we aren't copying anything gitlab-com/gl-infra/production#8162 (comment 1227401393)

Related issues

Checklist

See Definition of done.

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Required

• Merge Request Title, and Description are up to date, accurate, and descriptive
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Expected (please provide an explanation if not completing)

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