fix integration test for creating silences

to create correct silence with endsAt in the future

pkg/tests/api/alerting/api_alertmanager_test.go

@@ -12,11 +12,12 @@ import (
 	"testing"
 	"time"
 
-	"github.com/grafana/grafana/pkg/expr"
 	"github.com/prometheus/common/model"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
+	"github.com/grafana/grafana/pkg/expr"
+
 	apimodels "github.com/grafana/grafana/pkg/services/ngalert/api/tooling/definitions"
 	ngmodels "github.com/grafana/grafana/pkg/services/ngalert/models"
 	ngstore "github.com/grafana/grafana/pkg/services/ngalert/store"
@@ -44,6 +45,7 @@ func TestIntegrationAMConfigAccess(t *testing.T) {
 		EnableUnifiedAlerting: true,
 		DisableAnonymous:      true,
 		AppModeProduction:     true,
+		EnableLog:             true,
 	})
 
 	grafanaListedAddr, store := testinfra.StartGrafana(t, dir, path)
@@ -212,21 +214,22 @@ func TestIntegrationAMConfigAccess(t *testing.T) {
 	})
 
 	t.Run("when creating silence", func(t *testing.T) {
-		body := `
+		now := time.Now()
+		body := fmt.Sprintf(`
 		{
 			"comment": "string",
 			"createdBy": "string",
-			"endsAt": "2023-03-31T14:17:04.419Z",
 			"matchers": [
 			  {
 				"isRegex": true,
 				"name": "string",
 				"value": "string"
 			  }
 			],
-			"startsAt": "2021-03-31T13:17:04.419Z"
+			"startsAt": "%s",
+			"endsAt": "%s"
 		  }
-		`
+		`, now.Format(time.RFC3339), now.Add(10*time.Second).Format(time.RFC3339))
 
 		testCases := []testCase{
 			{