Set contentType in config as well for gcloud bucket config

Author: silverbackdan

src/Helper/Uploadable/UploadableFileManager.php

@@ -153,6 +153,9 @@ public function persistFiles(object $object): void
                 $stream,
                 [
                     'mimetype' => $file->getMimeType(),
+                    'metadata' => [
+                        'contentType' => $file->getMimeType()
+                    ]
                 ]
             );
             $classMetadata->setFieldValue($object, $fieldConfiguration->property, $path);