Fix PrometheusRule namespace

Signed-off-by: João Vilaça <jvilaca@redhat.com>

pkg/monitoring/monitoring.go

@@ -41,7 +41,7 @@ func RenderMonitoring(manifestDir string, monitoringAvailable bool) ([]*unstruct
 		return nil, errors.Wrap(err, "failed to setup monitoring rules")
 	}
 
-	promRule, err := rules.BuildPrometheusRule(monitoringNamespace)
+	promRule, err := rules.BuildPrometheusRule(operandNamespace)
 	if err != nil {
 		return nil, errors.Wrap(err, "failed to build PrometheusRule")
 	}