chore: Improve canary test stability

[mattcreaser]

• PR title and description conform to Pull Request guidelines.

Issue #, if available:

Description of changes:
Improves the canary tests across categories with similar improvements that were added to the auth category in #3143

Generally this involved fixing two classes of issues:

1. Running assertions (or calling fail) in callbacks from Amplify since these operate on background threads. Instead of failing the test such assertions will cause the test process to crash, losing any information about what went wrong.
2. Using a CountdownLatch and not checking the return value of await. Such tests could cause various incorrect errors to be surfaced.

Both of these are generally addressed by using the Synchronous* test utility classes, which wrap Amplify calls to block the thread for results, propagate errors back to the calling thread, and internally do the proper handling of timeouts.

This may cause some tests to fail less often and, especially, should make any failures easier to diagnose. As an example, a device in Device Farm that is having connectivity issues would run in to issue (1) above, so the error in the test report would just be "test process crashed" - which may even be reported for a different test if (2) also came in to play. Now in this situation it will report the actual error that occurred (e.g. UnknownHostException) for the actual test that it happened in.

How did you test these changes?
Tests should pass.

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)
• Ensure commit message has the appropriate scope (e.g fix(storage): message, feat(auth): message, chore(all): message)

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

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 54.69%. Comparing base (e7db5a7) to head (779c528).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3153      +/-   ##
==========================================
- Coverage   54.70%   54.69%   -0.01%     
==========================================
  Files        1046     1046              
  Lines       31251    31251              
  Branches     4690     4690              
==========================================
- Hits        17096    17093       -3     
- Misses      12330    12331       +1     
- Partials     1825     1827       +2     

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