Returns the root name of the variables used to store the configuration.
Based on the entity type and bundle, the variables used to store the configuration will have a common root name.
string $entity_type: A string representing the entity type.
string $bundle: A string representing the bundle.
string The root name of the variables.
function language_get_default_configuration_settings_key($entity_type, $bundle) {
// Replace all the characters that are not letters, numbers or "_" with "_".
$entity_type = preg_replace('/[^0-9a-zA-Z_]/', "_", $entity_type);
$bundle = preg_replace('/[^0-9a-zA-Z_]/', "_", $bundle);
return $entity_type . '.' . $bundle . '.language.default_configuration';
}