I18N of protected_tags directory

This is one of many MRs opened in order to improve the overall
internationalisation of the GitLab codebase.

This commit only targets Vanilla JS files.

i18n documentation
https://docs.gitlab.com/ee/development/i18n/externalization.html

app/assets/javascripts/protected_tags/protected_tag_access_dropdown.js

+import { __ } from '~/locale';
+
 export default class ProtectedTagAccessDropdown {
   constructor(options) {
     this.options = options;
@@ -15,7 +17,7 @@ export default class ProtectedTagAccessDropdown {
         if ($el.is('.is-active')) {
           return item.text;
         }
-        return 'Select';
+        return __('Select');
       },
       clicked(options) {
         options.e.preventDefault();

app/assets/javascripts/protected_tags/protected_tag_create.js

 import $ from 'jquery';
 import ProtectedTagAccessDropdown from './protected_tag_access_dropdown';
 import CreateItemDropdown from '../create_item_dropdown';
+import { __ } from '~/locale';
 
 export default class ProtectedTagCreate {
   constructor() {
@@ -27,7 +28,7 @@ export default class ProtectedTagCreate {
     // Protected tag dropdown
     this.createItemDropdown = new CreateItemDropdown({
       $dropdown: this.$form.find('.js-protected-tag-select'),
-      defaultToggleLabel: 'Protected Tag',
+      defaultToggleLabel: __('Protected Tag'),
       fieldName: 'protected_tag[name]',
       onSelect: this.onSelectCallback,
       getData: ProtectedTagCreate.getProtectedTags,

app/assets/javascripts/protected_tags/protected_tag_edit.js

 import flash from '../flash';
 import axios from '../lib/utils/axios_utils';
 import ProtectedTagAccessDropdown from './protected_tag_access_dropdown';
+import { __ } from '~/locale';
 
 export default class ProtectedTagEdit {
   constructor(options) {
@@ -47,7 +48,11 @@ export default class ProtectedTagEdit {
       .catch(() => {
         this.$allowedToCreateDropdownButton.enable();
 
-        flash('Failed to update tag!', 'alert', document.querySelector('.js-protected-tags-list'));
+        flash(
+          __('Failed to update tag!'),
+          'alert',
+          document.querySelector('.js-protected-tags-list'),
+        );
       });
   }
 }

locale/gitlab.pot

@@ -4888,6 +4888,9 @@ msgstr ""
 msgid "Failed to update issues, please try again."
 msgstr ""
 
+msgid "Failed to update tag!"
+msgstr ""
+
 msgid "Failed to update."
 msgstr ""
 
@@ -9552,6 +9555,9 @@ msgstr ""
 msgid "Protected Environments"
 msgstr ""
 
+msgid "Protected Tag"
+msgstr ""
+
 msgid "ProtectedEnvironment|%{environment_name} will be writable for developers. Are you sure?"
 msgstr ""