make a Fuchsia installer image from a remote build host

    usage: fx mkinstaller-remote [<host> [<host_dir>]] <mkinstaller args>
     host      Remote build host name; defaults to the last-used host.
     host_dir  Fuchsia root dir on the remote build host; defaults to the last-used dir or ~/fuchsia.

     Use --help to get a full list of mkinstaller args.

[mkinstaller-remote source code](https://cs.opensource.google/fuchsia/fuchsia/+/main:tools/devshell/contrib/mkinstaller-remote)