Toolbox Cron backups add Istio injection

For testing I used the below values (in addition to whatever values you usually use). You can change the schedule as needed, but the job can take a minute or two so its best to not run too frequently:

addons:
  gitlab:
    enabled: true
    git:
      tag: null
      branch: 155-toolbox-cron-backups
    values:
      gitlab:
        toolbox:
          backups:
            cron:
              enabled: true
              schedule: "*/15 * * * *"

(if you want to see the before and after use the same values without the git overrides and you will see the error mentioned in the issue)

Package MR for #155 (closed)