test: increase test coverage

src/app/settings/settings.interface.ts

@@ -1,6 +1,12 @@
 import { Language } from './language.enum';
 import { Theme } from './theme.enum';
 
+/** Settings key in storage */
+export const SETTINGS_STORE_KEY = 'settings';
+
+/**
+ * Contains all types of supported video players
+ */
 export enum VideoPlayer {
     VideoJs = 'videojs',
     Html5Player = 'html5',