How to import a display mode configuration from a custom module
Features may help you solve this problem - https://www.drupal.org/project/features . If you have Features enabled, and the module include a mymodule.features.yml file in it, it can gracefully handle updating existing configuration like this without throwing the nasty error. You can do a drush fr mymodule and it will import the new configuration without having to delete existing. As 4x4 was mentioning, this wouldn't be ideal for configuration site owners are changing, but if it's something you're updating and maintaining as the developer, it's an ideal route to go.