Fix Flaky Tests

Investigate flaky tests in the repo and propose fixes to improve stability. High-level process:

1. Run tests in the repo to look for flakes.
   • Consider using Bazel's --runs_per_test flag to easily find flakes.
   • Be cognizant of not exhausting all the resources on the current machine, run a subset of tests at a time such as bazel test //packages/core/....
2. Once you find some flakes, focus on one at a time.
3. Create a new branch named flakes/${relevantNameFromTest}.
4. Reproduce the flake to the best of your ability.
   • Consider using --test_env JASMINE_RANDOM_SEED=1234 to replicate the broken test ordering.
5. Debug the test to understand the failure mode.
   • Consider temporarily disabling / skipping other tests with xit and fit to narrow down where the flake might be coming from if multiple tests are influencing each other.
   • Consider temporarily ignoring Firefox tests with --test_tag_filters -firefox if the flake does not appear to be browser specific.
   • Consider using --test_sharding_strategy disabled to run the test in a single shard.
   • Try to understand why the test was flaky, not just why it failed. Understanding the inconsistency is important to finding the correct fix.
6. Attempt a fix and validate with --runs_per_test.
   • Iterate on the fix until you have something which appears to work.
   • If you find yourself stuck and not making meaningful progress, note down what you've learned/where you're struggling, commit what you have, look for another flake to fix, and continue. At the end, surface to the user what you failed to fix.
   • Don't try to make significant changes to Angular's runtime behavior, focus just on making the test pass/fail consistently.
7. Commit the change with relevant details in the commit message and move on to the next test.
   • Be sure to include your theory of why the test was flaky and how this fix eliminates or reduces that flakiness.
8. Iterate as many times as the user requests you to (default 5 branches if not otherwise specified).
9. Once you can't find any flaky tests or have iterated as many times as requested, stop and inform the user what you found and fixed.

Additional notes:

• Multiple fixes including the same/related files can go in the same commit or multiple commits on the same branch.
• Distinct test fixes should go in different branches, make a new one for each investigation.
• You may push these branches to origin, but do not create PRs for them.