Verify Bazel CI test changes are working as expected

[BenHenning]

From #1904:

• Verify that the workflows behave correctly on forks where caching has to be disabled
• Verify that the automatic at-head builds on develop work correctly with the new workflow changes
• Verify that manual workflow runs work correctly with the changes
• (Once 1-3 are completed) Set the new 'Run test' workflow as required
• (After 4) Verify that the requirement doesn't break when creating a PR that doesn't run any affected tests (thereby not running the required workflow)
• Send out a communication explaining the new tests, what people can expect, how to investigate issues, and who to contact
• Fix whatever is going on with this: https://github.com/oppia/oppia-android/pull/2671/checks?check_run_id=1908497857 (affected targets issues)
• Fix hanging compute affected targets actions when Bazel files themselves are changed (Fix #2585: Adding BUILD.bazel in //app/viewmodel/ #2648)

[BenHenning]

Running on develop: https://github.com/oppia/oppia-android/actions/runs/559499045 (strange JVM crash failure, but tests otherwise look operational).

[BenHenning]

Manual run kicked off: https://github.com/oppia/oppia-android/actions/runs/560109387. Seems to be working, but I'll check in just to make sure before checking the above.

[BenHenning]

For the fork test, will need to wait for a new PR to be created to check.

[BenHenning]

Ugh, looks like the check might be failing when no targets are computed: https://github.com/oppia/oppia-android/actions/runs/560112155.

[BenHenning]

I think we can conclude that manually triggering the workflows does work, and that the no affected targets check is NOT working. I'm fairly confident once the underlying issue is fixed that the conclusion task should pass & thus work when its required, so I may preemptively check that once #2696 is verified as working & merged in.

[BenHenning]

/cc @fsharpasharp in case you're interested in following along on this.

[BenHenning]

Another issue: #2695.

[BenHenning]

Confirming forks fail at least due to the key management piece: #2690. There's probably a check missing here.

[BenHenning]

Per https://github.com/oppia/oppia-android/pull/2690/checks?check_run_id=1885145971 it looks like the fork check is failing unexpectedly. Those actions weren't supposed to run which is why they're failing.

[BenHenning]

Interestingly https://github.com/oppia/oppia-android/pull/2320/checks?check_run_id=1886178465 ran successfully so the computed affected tests bit is not yet reliable.