In the current e2e tests we are using the metrics endpoint to check that the v2 binary is up and ready for tests:

   e2e_integration.go:98: Checking if Jaeger-v2 is available on http://localhost:8888/metrics

Since we already introduced a health check extension (#5831), we should be using that instead of /metrics.

Changes required:

• configure health check extension in other config files ([v2] Configure healthcheck extension #5831 only did it in all-in-one)
• change e2e test to ping the /status endpoint of the health check extension instead of /metrics. Wait for statusOk in the JSON, not just HTTP 200.