OCPBUGS-8993: add namespace label to InstallPlanStepAppliedWithWarnings (#3012)

The alerting consistency guide [1] requires the following:

`Alerts SHOULD include a namespace label indicating the alert's source.`

This change updates the expression of InstallPlanStepAppliedWithWarnings
to aggregate the result by namespace.

[1] https://github.com/openshift/enhancements/blob/master/enhancements/monitoring/alerting-consistency.md

Signed-off-by: Simon Pasquier <[email protected]>
Upstream-repository: operator-lifecycle-manager
Upstream-commit: 2976198c8e22837af8b7ade704212a536fa37071

Author: simonpasquier

manifests/0000_90_olm_01-prometheus-rule.yaml

@@ -36,7 +36,7 @@ spec:
     - name: olm.installplan.rules
       rules:
         - alert: InstallPlanStepAppliedWithWarnings
-          expr: sum(increase(installplan_warnings_total[5m])) > 0
+          expr: sum by(namespace) (increase(installplan_warnings_total[5m])) > 0
           labels:
             severity: warning
           annotations:

staging/operator-lifecycle-manager/deploy/chart/templates/0000_90_olm_01-prometheus-rule.yaml

@@ -34,7 +34,7 @@ spec:
   - name: olm.installplan.rules
     rules:
     - alert: InstallPlanStepAppliedWithWarnings
-      expr: sum(increase(installplan_warnings_total[5m])) > 0
+      expr: sum by(namespace) (increase(installplan_warnings_total[5m])) > 0
       labels:
         severity: warning
       annotations: