Drupal 8 - Add to views field link class when fields is taxonomy referenced entity

tag_preprocess.php

// Drupal 8 developper http://codenator.org
function THEMENAME_preprocess_views_view_field__field_tags(&$vars) {
  $rendered = $vars['field']->getItems($vars['row']);
  //added icon on front of tags
  $renderedArray[] = [
    '#markup' => '<span class="glyphicon glyphicon-tags" aria-hidden="true"></span>'
  ];
  if (is_array($rendered)) {
    foreach ($rendered as $one) {
      //dpm($one['rendered']);
      $one['rendered']['#attributes'] = [
        'class' => [
          'btn',
          'btn-xs',
          'btn-default',
          'btn-tags'
        ]
      ];
      $renderedArray[] = $one['rendered'];
    }
  }
  $vars['output'] = $renderedArray;
}