Issue #3148053 by grace_karuna: Preparing the module for Drupal 9 compatibility.

I endorse the work grace_karuna did in the issue queue. So I am committing the patch in order to be able to use this repository within a composer.json declaration as suggested in https://www.drupal.org/docs/upgrading-drupal/upgrading-from-drupal-8-to-drupal-9-or-later#s-installing-drupal-8-only-contributed-module-with-drupal-9-patch