[1] HTTP Headers and Query String Parameters - Cloud Storage — Google Cloud Platform ( 版) <https://cloud.google.com/storage/docs/reference-headers#extension>
If you do not specify a content type when you upload an object, the Google Cloud Storage system defaults to binary/octet-stream when it serves the object.
[2] Migrating from Amazon S3 to Google Cloud Storage - Cloud Storage — Google Cloud Platform ( 版) <https://cloud.google.com/storage/docs/migrating#migration-simple>
Change any existing x-amz-* headers to corresponding x-goog-* headers.