[ISSUE #6817] Replace RocketMQ e2e sleeps with Awaitility

[yykaue]

Fixes #6817.

Changes

• Start the RocketMQ consumer before sending the request.
• Replace fixed 30-second sleeps with bounded Awaitility polling.
• Ensure the RocketMQ consumer is reliably shut down.
• Add Awaitility as a managed test dependency for the RocketMQ e2e case.

Verification

• Ran mvn -f shenyu-e2e/pom.xml -pl :shenyu-e2e-case-logging-rocketmq -am test-compile.
• All 6 reactor modules completed successfully.
• Checkstyle completed with 0 violations.

@Aias00, could you please help review this PR? Thank you!

[Aias00]

Reviewed the changes and did not find blocking issues.

[dengliming]

This is a good step forward, but I think we still need an explicit readiness check before sending the request. Right now we start the consumer and immediately issue the HTTP call, then wait for the log to appear. In CI, the flaky part seems to be that the route/logging path may not be fully ready yet when that request is sent, so we can still miss the log and time out even though RocketMQ itself is healthy.

Could we split this into two phases?

1. wait until the gateway route is actually serving successfully
2. then send a fresh request and await the RocketMQ log for that request

That would make the test assert “logging works after the system is ready” rather than depending on startup timing.

[Aias00]

Heads-up (PMC Aias00): your PR's CI failures are in shared infrastructure checks (k8s-examples-http, e2e-case-logging-rocketmq, build-docker-images) that are currently failing across many unrelated PRs. This looks like a CI-environment issue, not a problem with your change. Please re-run the failed checks; the code change itself appears fine. No code changes needed for these specific failures.