Nit: Maybe fix a flaky testAuthenticationInBrowser test

[oskirby]

Description

Spotted in the wild, a flaky testAuthenticationInBrowser and I think this can be fixed simply by waiting for the stackview to load.

Reference

None

Checklist

• [ ] My code follows the style guidelines for this project
• [ ] I have not added any packages that contain high risk or unknown licenses (GPL, LGPL, MPL, etc. consult with DevOps if in question)
• [ ] I have performed a self review of my own code
• [ ] I have commented my code PARTICULARLY in hard to understand areas
• [ ] I have added thorough tests where needed