Update JUnit4 instrumentation to fire test suite events for Bazel

[daniel-mohedano]

What Does This Do

• Introduces proper handling for Bazel's JUnit tests runner suite events by:
  • Removing the previous temporary solution of lazy starting suites.
  • Introduces a new instrumentation for fireTestSuiteStarted and fireTestSuiteFinished methods to unwrap the notifiers and propagate the firing to our tracing listener.

Motivation

Bazel's default JUnit4 configuration for running test suites introduces changes that mess with our instrumentation:

1. Bazel's JUnit entry-point is through BazelTestRunner.main(), which builds a JUnit4Runner (does not inherit org.junit.runner.Runner) and calls run().
2. JUnit4Runner.run() instantiates JUnitCore, registers its run listeners and calls core.run(cancellableRequest).
3. JUnitCore creates a fresh RunNotifier (from now on A) and registers the listeners on it.
4. The request is run with a custom CancellableRunner (extends org.junit.runner.Runner). Its run(A) does currentNotifier = new ThreadSafeRunNotifier(A); delegate.run(currentNotifier);.
5. ThreadSafeRunNotifier extends RunNotifierWrapper extends RunNotifier, so currentNotifier (from now on B) has its own private inherited listeners field.
6. The real runner.run(B) executes.
7. Our instrumentation modifies the call to do B.addListener(tracingListener), but Bs implementation overrides the method to call delegate.addListener(tracingListener); so our listener lands on A.listeners.
8. The real runner fires events such as test suite starts with B.fireTestSuiteStarted(...).
9. The wrapper does not override test suite methods, so it is resolved as RunNotifier.fireTestSuiteStarted(...) invoked with this = B. This iterates over B.listeners, which is empty.
10. The wrapper does forward regular test events with delegate.fireTest...(...) by overriding the methods

All this caused test suite events to be dropped.

Contributor Checklist

• Format the title according to the contribution guidelines
• Assign the type: and (comp: or inst:) labels in addition to any other useful labels
• Avoid using close, fix, or any linking keywords when referencing an issue
  Use solves instead, and assign the PR milestone to the issue
• Update the CODEOWNERS file on source file addition, migration, or deletion
• Update public documentation with any new configuration flags or behaviors

Jira ticket: [PROJ-IDENT]

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[cit-pr-commenter-54b7da]

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Scenario	Overhead (%)
agent	56.98
agentEvpProxy	56.37

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agentless	36.40
agentlessCodeCoverage	43.61
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agentless	81.20
agentlessCodeCoverage	95.83
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