javascript/api/src: Fix a bug where the stream id doesn't match the flow id for the rpc.
javascript/api/src: Fix a bug where the stream id doesn't match the flow
id for the rpc.

Change-Id: I5c193d8b8965b59ed6d8ac36c7c66e1bbf05dbe6

vanadium/js,vanadium/js,vanadium/js,vanadium/js