[Dual writer] Read kind value passed as dualwriter's argument (#91113)

* Include kind on the dualwriter to be used on metrics

* Use kind as argument

* Skip dual writer in mode4

pkg/services/apiserver/builder/helper.go

@@ -174,10 +174,14 @@ func InstallAPIs(
 			if err != nil {
 				return nil, err
 			}
-			if currentMode == grafanarest.Mode0 {
+			switch currentMode {
+			case grafanarest.Mode0:
 				return legacy, nil
+			case grafanarest.Mode4:
+				return storage, nil
+			default:
 			}
-			return grafanarest.NewDualWriter(currentMode, legacy, storage, reg), nil
+			return grafanarest.NewDualWriter(currentMode, legacy, storage, reg, key), nil
 		}
 	}