static createLocalization_() {
    /** @type {string} */
    const fallbackLocale = 'en';

    /** @type {!shaka.ui.Localization} */
    const localization = new shaka.ui.Localization(fallbackLocale);
    shaka.ui.Locales.addTo(localization);
    localization.changeLocale(navigator.languages || []);

    return localization;
  }
Create a localization instance already pre-loaded with all the locales that
we support.

@return {!shaka.ui.Localization}
@private