dashboard: fix import dashboard with alert rule

Importing a dashboard with alert rule(s) should be possible without receiving invalid
alert data error. This fix reverts the import logic to how it worked before Grafana v5.0,
that is import will allow dashboard with alert rule(s) but no alerts will be created.
After an import the user will need to update the dashboard for the alerts to be created.
Fixes #11227

(cherry picked from commit 87284d284e)

pkg/plugins/dashboard_importer.go

@@ -80,7 +80,7 @@ func ImportDashboard(cmd *ImportDashboardCommand) error {
 		User:      cmd.User,
 	}
 
-	savedDash, err := dashboards.NewService().SaveDashboard(dto)
+	savedDash, err := dashboards.NewService().ImportDashboard(dto)
 
 	if err != nil {
 		return err

pkg/services/dashboards/dashboard_service.go

@@ -13,6 +13,7 @@ import (
 // DashboardService service for operating on dashboards
 type DashboardService interface {
 	SaveDashboard(dto *SaveDashboardDTO) (*models.Dashboard, error)
+	ImportDashboard(dto *SaveDashboardDTO) (*models.Dashboard, error)
 }
 
 // DashboardProvisioningService service for operating on provisioned dashboards
@@ -214,6 +215,20 @@ func (dr *dashboardServiceImpl) SaveDashboard(dto *SaveDashboardDTO) (*models.Da
 	return cmd.Result, nil
 }
 
+func (dr *dashboardServiceImpl) ImportDashboard(dto *SaveDashboardDTO) (*models.Dashboard, error) {
+	cmd, err := dr.buildSaveDashboardCommand(dto, false)
+	if err != nil {
+		return nil, err
+	}
+
+	err = bus.Dispatch(cmd)
+	if err != nil {
+		return nil, err
+	}
+
+	return cmd.Result, nil
+}
+
 type FakeDashboardService struct {
 	SaveDashboardResult *models.Dashboard
 	SaveDashboardError  error
@@ -230,6 +245,10 @@ func (s *FakeDashboardService) SaveDashboard(dto *SaveDashboardDTO) (*models.Das
 	return s.SaveDashboardResult, s.SaveDashboardError
 }
 
+func (s *FakeDashboardService) ImportDashboard(dto *SaveDashboardDTO) (*models.Dashboard, error) {
+	return s.SaveDashboard(dto)
+}
+
 func MockDashboardService(mock *FakeDashboardService) {
 	NewService = func() DashboardService {
 		return mock