Use dw dynamic config (#91222)

* Remove kubernetesPlaylists feature_toggle

* Remove unified_storage_mode

* Remove double import

* Regenerate feature-toggles

* Read from config instead from feature_toggle

* cover scenario for when unified storage is not defined

pkg/setting/setting.go

@@ -29,6 +29,7 @@ import (
 	"github.com/grafana/grafana-plugin-sdk-go/backend/gtime"
 
 	"github.com/grafana/grafana/pkg/apimachinery/identity"
+	grafanarest "github.com/grafana/grafana/pkg/apiserver/rest"
 	"github.com/grafana/grafana/pkg/infra/log"
 	"github.com/grafana/grafana/pkg/util"
 	"github.com/grafana/grafana/pkg/util/osutil"
@@ -520,6 +521,9 @@ type Cfg struct {
 
 	//Short Links
 	ShortLinkExpiration int
+
+	// Unified Storage
+	UnifiedStorage map[string]grafanarest.DualWriterMode
 }
 
 // AddChangePasswordLink returns if login form is disabled or not since