fix(updatenotification): Adjust tests for changed IAppConfig

[susnux]

• Follow up on feat: Provide app-updated notifications for users #43967 - This was already fixed there but probably lost in last rebase.

Summary

Fix unit tests to use correct app config.

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)