Alerting: Fix updating notification channels in legacy (#45302)

The problem here is that without the orgID we ignore the lookup of the existing notification channel just before updating and end up failing the update because there is no channel available.

pkg/services/alerting/service.go

@@ -2,6 +2,7 @@ package alerting
 
 import (
 	"context"
+	"fmt"
 
 	"github.com/grafana/grafana/pkg/bus"
 	"github.com/grafana/grafana/pkg/models"
@@ -77,6 +78,7 @@ func (s *AlertNotificationService) UpdateAlertNotification(ctx context.Context,
 
 	model := models.AlertNotification{
 		Id:       cmd.Id,
+		OrgId:    cmd.OrgId,
 		Name:     cmd.Name,
 		Type:     cmd.Type,
 		Settings: cmd.Settings,
@@ -137,7 +139,11 @@ func (s *AlertNotificationService) createNotifier(ctx context.Context, model *mo
 			return nil, err
 		}
 
-		if query.Result != nil && query.Result.SecureSettings != nil {
+		if query.Result == nil {
+			return nil, fmt.Errorf("unable to find the alert notification")
+		}
+
+		if query.Result.SecureSettings != nil {
 			var err error
 			secureSettingsMap, err = s.EncryptionService.DecryptJsonData(ctx, query.Result.SecureSettings, setting.SecretKey)
 			if err != nil {