Implements hook_entity_form_display_alter().
function entity_test_entity_form_display_alter(EntityFormDisplay $form_display, $context) {
// Make the field_test_text field 42 characters for entity_test_mul.
if ($context['entity_type'] == 'entity_test') {
if ($component_options = $form_display
->getComponent('field_test_text')) {
$component_options['settings']['size'] = 42;
$form_display
->setComponent('field_test_text', $component_options);
}
}
}