Dynamic definition of FileEntityNormalizer depends on hal, not rest

Problem/Motivation

FileEntityNormalizer extends a class in hal, but the service is defined even if only rest is enabled.

FileEntityServiceProvider.php:

    if (isset($modules['rest'])) {
      // Add a normalizer service for file entities.
      $service_definition = new Definition('Drupal\file_entity\Normalizer\FileEntityNormalizer', array(

FileEntityNormalizer.php:

use Drupal\hal\Normalizer\ContentEntityNormalizer;

class FileEntityNormalizer extends ContentEntityNormalizer {

Proposed resolution

Define only if hal is enable.

Remaining tasks

User interface changes

API changes

Data model changes