Correct namespace for SimpleContentAccessNotAvailable

And possibly other alerts.  Declaring namespace labels on alerts makes it easy to find the source or affected resource, as described here. But because Insights alerts are based on metrics exported by the cluster-version operator, they inherit source information from the CVO, and end up looking like:

ALERTS{alertname="SimpleContentAccessNotAvailable", alertstate="firing", condition="SCAAvailable", endpoint="metrics", instance="10.58.57.116:9099", job="cluster-version-operator", name="insights", namespace="openshift-cluster-version", pod="cluster-version-operator-5d8579fb58-p5hfn", prometheus="openshift-monitoring/k8s", reason="NotFound", receive="true", service="cluster-version-operator", severity="info"}

Adding namespace: openshift-insights to the labels block for InsightsDisabled and SimpleContentAccessNotAvailable would avoid this confusion.

You might also want to clear the job and service labels as irrelevant source information. And you might want to clear the pod label to avoid churning alerts when the CVO rolls out a new pod. You can get the label clearing by wrapping the expr with max without (job, pod, service) (...) or similar.