Add availability probe for image controller

[mshaposhnik]

What does this PR do?

Checks Quay cnnectivity and credendials validity,
reports as a redhat_appstudio_imagecontroller_global_quay_app_available metric.

What issues does this PR fix or reference?

https://issues.redhat.com/browse/STONEBLD-1931

How to check:

Deploy to Openshift or K8S, check the redhat_appstudio_imagecontroller_global_quay_app_available metric value shoud be 1:

kubectl exec $(kubectl get pods -n image-controller -l control-plane=controller-manager --no-headers -o custom-columns=":metadata.name" ) -c manager -n image-controller  --  curl -s  http://localhost:8080/metrics | grep redhat_appstudio_imagecontroller_global_quay_app_available

[openshift-ci]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[mshaposhnik]

/retest

[tkdchen]

LGTM

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud

[mshaposhnik]

/retest

[mshaposhnik]

/retest

[openshift-ci]

@mshaposhnik: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
ci/prow/image-controller-e2e	8375566	link	true	/test image-controller-e2e

Full PR test history. Your PR dashboard.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository. I understand the commands that are listed here.