block_content_entity_type_alter

block_content_entity_type_alter(array &$entity_types)

function block_content_entity_type_alter(array &$entity_types) {
  /** @var $entity_types \Drupal\Core\Entity\EntityTypeInterface[] */
  // Add a translation handler for fields if the language module is enabled.
  if (\Drupal::moduleHandler()->moduleExists('language')) {
    $translation = $entity_types['block_content']->get('translation');
    $translation['block_content'] = TRUE;
    $entity_types['block_content']->set('translation', $translation);
  }
}