Alerting: Metrics should have the label org instead of user (#39353) (#39365)

An user within Grafana has a completely different meaning. Multi-tenancy is done via Organizations as a top-level concept.

(cherry picked from commit 35e5bfce40)

Co-authored-by: gotjosh <josue@grafana.com>

pkg/services/ngalert/metrics/ngalert.go

@@ -129,7 +129,7 @@ func newSchedulerMetrics(r prometheus.Registerer) *Scheduler {
 				Name:      "rule_evaluations_total",
 				Help:      "The total number of rule evaluations.",
 			},
-			[]string{"user"},
+			[]string{"org"},
 		),
 		// TODO: once rule groups support multiple rules, consider partitioning
 		// on rule group as well as tenant, similar to loki|cortex.
@@ -140,7 +140,7 @@ func newSchedulerMetrics(r prometheus.Registerer) *Scheduler {
 				Name:      "rule_evaluation_failures_total",
 				Help:      "The total number of rule evaluation failures.",
 			},
-			[]string{"user"},
+			[]string{"org"},
 		),
 		EvalDuration: promauto.With(r).NewSummaryVec(
 			prometheus.SummaryOpts{
@@ -150,7 +150,7 @@ func newSchedulerMetrics(r prometheus.Registerer) *Scheduler {
 				Help:       "The duration for a rule to execute.",
 				Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
 			},
-			[]string{"user"},
+			[]string{"org"},
 		),
 	}
 }
@@ -166,7 +166,7 @@ func newStateMetrics(r prometheus.Registerer) *State {
 				Name:      "rule_group_rules",
 				Help:      "The number of rules.",
 			},
-			[]string{"user"},
+			[]string{"org"},
 		),
 		AlertState: promauto.With(r).NewGaugeVec(prometheus.GaugeOpts{
 			Namespace: Namespace,