Properly use dependency injection and services

Follow-up to #2490966: [Meta] Replace deprecated usage of entity_create with a direct call to the entity type class →

entity_create() function is going to be deprecated so we shouldn't use it anymore. When the entity type is known we should directly call ::create().

Proposed resolution

Replace the deprecated call to entity_create() by a proper call to ::create().

Before:

entity_create('file', $field_values)->save();

After:

use Drupal\file\Entity\File;
File::create($field_values)->save();