fix(auth): Fix for checking current preferred type before setting the MFAType as enabled to ensure the current preference is not cleared out

[gpanshu]

Fix for checking current preferred type before setting the MFAType as enabled to ensure the current preference is not cleared out

• PR title and description conform to Pull Request guidelines.

Issue #, if available:

Description of changes: For updating of mfa preferences we were just updating based on what customer had provided without taking into consideration what current preferences were which meant we could get into scenarios where 2 preferences were set to preferred. Hence in this PR I aim to fix that by prefetching the current preferences before updating it.

How did you test these changes?
(Please add a line here how the changes were tested)

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-commenter]

Codecov Report

Merging #2580 (2bbb89d) into main (45d19c1) will increase coverage by 0.03%.
The diff coverage is 54.54%.

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

@@            Coverage Diff             @@
##             main    #2580      +/-   ##
==========================================
+ Coverage   41.72%   41.76%   +0.03%     
==========================================
  Files         900      900              
  Lines       28791    28814      +23     
  Branches     4082     4093      +11     
==========================================
+ Hits        12012    12033      +21     
- Misses      15459    15462       +3     
+ Partials     1320     1319       -1     

[tylerjroach]

Discovered an issue that can be seen in the described scenario.'

Say TOTP was enabled and preferred.

Next, if a user were to set SMS as enabled and preferred, the update call would also attempt to set TOTP as preferred due to the previous setting.

2 MFA settings can't be preferred at the same time.