CHW-8306 HFCommitFileEncoding

commit file content could not be decoded; only base64 encoding is supported

Default message: commit file content could not be decoded; only base64 encoding is supported
HTTP status: 400 (client)

Problem. A file entry was rejected. Cause. Its content used an unsupported encoding, or the base64 payload failed to decode. Fix. Send file content base64-encoded in the entry’s content field. HTTP 400.