Variable theme_default is overriden after enabling feature

Steps to reproduce the issue

1. Install Drupal with features and strongarm.
2. Set default theme to Seven.
3. Run drush fe theme_test variable:theme_default.
4. Reinstall Drupal with features, strongarm and theme_test.
5. Go to the front page. Theme is Bartik.
6. Go to /admin/config/development/strongarm. Check that theme_default is in state overridden.

What I would expect

I would expect that after enabling the feature the strongarm variables would be imported in the database. In the case on theme_default this doesn't seem to work. Also the drush command strongarm-revert won't revert the theme_default value as expected.