chore(auth): Move auto-sign-in to usecase

[mattcreaser]

• PR title and description conform to Pull Request guidelines.

Issue #, if available:

Description of changes:
Moves the autoSignIn functionality into a use case. This PR also adds unit test coverage that was missing for this functionality.

How did you test these changes?

• Unit tests
• Test App

Documentation update required?

• No
• Yes (Please include a PR link for the documentation update)

General Checklist

• Added Unit Tests
• Added Integration Tests
• Security oriented best practices and standards are followed (e.g. using input sanitization, principle of least privilege, etc)

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov]

Codecov Report

Attention: Patch coverage is 72.46377% with 19 lines in your changes missing coverage. Please review.

Project coverage is 41.76%. Comparing base (7f874ed) to head (3a3e7ce).
Report is 58 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3008      +/-   ##
==========================================
- Coverage   44.01%   41.76%   -2.26%     
==========================================
  Files         926      991      +65     
  Lines       30485    31505    +1020     
  Branches     4351     4642     +291     
==========================================
- Hits        13419    13159     -260     
- Misses      15601    16923    +1322     
+ Partials     1465     1423      -42     

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