[Meta] Improving adoption of Prometheus

This is a tracking issue, to collect the various issues we have to improve the adoption of Prometheus related features.

• Automatic detection of Prometheus metrics (https://gitlab.com/gitlab-org/gitlab-ce/issues/30369)
• Single click deploy of Prometheus to k8s (https://gitlab.com/gitlab-org/gitlab-ce/issues/28916)
• Automatically detect a Prometheus server running in k8s cluster (https://gitlab.com/gitlab-org/gitlab-ce/issues/31598)
• Integrated browser testing (https://gitlab.com/gitlab-org/gitlab-ee/issues/3046)