Merge branch '45070-prometheus-integration-via-kubernetes-is-broken' into 'master'

Override Prometheus service name to fix integration with GitLab.

Closes #45070

See merge request gitlab-org/gitlab-ce!18206

changelogs/unreleased/45070-prometheus-integration-via-kubernetes-is-broken.yml

+---
+title: Work around Prometheus Helm chart name changes to fix integration
+merge_request: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/18206/
+author: joshlambert
+type: fixed

vendor/prometheus/values.yaml

@@ -14,6 +14,7 @@ rbac:
   create: false
 
 server:
+  fullnameOverride: "prometheus-prometheus-server"
   image:
     tag: v2.1.0