Issue #3303855 by idebr: Fix deprecations triggered in automated tests

class AjaxCommentsSettingsFormTest extends CommentTestBase {

  /**

   * Modules to install.

   *

   * @var array

   * {@inheritdoc}

   */

  public static $modules = [

    'system',

    'block',

    'comment',

    'node',

  protected static $modules = [

    'ajax_comments',

  ];

    // Check that the page loads.

    $this->assertSession()->statusCodeEquals(200);

    $this->assertSession()->pageTextContains(t("Enable Ajax Comments on the comment fields' display settings"));

    $this->clickLink(t('Content: Article'));

    $this->assertSession()->addressEquals('/admin/structure/types/manage/article/display', [], 'There is a link to the entity view display form for articles.');

    $this->clickLink('Content: Article');

    $this->assertSession()->addressEquals('/admin/structure/types/manage/article/display');

    $this->assertSession()->statusCodeEquals(200);

    // Open comment settings.

    // Disable ajax comments.

    $this->submitForm(['fields[comment][settings_edit_form][third_party_settings][ajax_comments][enable_ajax_comments]' => '0'], 'comment_plugin_settings_update');

    // Save display mode.

    $this->submitForm([], t('Save'));

    $this->submitForm([], 'Save');

    $this->assertSession()->statusCodeEquals(200);

  }

  /**

   * {@inheritdoc}

   */

  public static $modules = [

  protected static $modules = [

    'system',

    'ajax_comments',

    'node',