fix(material/theme): unselected theme picker

Fix unselected theme picker when localStorage is empty.

Fixes #204

Author: kian23kpt

material.angular.io/src/app/shared/theme-picker/theme-picker.ts

@@ -75,6 +75,12 @@ export class ThemePicker implements OnInit, OnDestroy {
     const themeName = this._themeStorage.getStoredThemeName();
     if (themeName) {
       this.selectTheme(themeName);
+    } else {
+      this.themes.find(themes => {
+        if (themes.isDefault === true) {
+          this.selectTheme(themes.name);
+        }
+      });
     }
   }