setup Linux firewall rules to allow Fuchsia device and emulator traffic.

    Setup Linux uncomplicated firewall (ufw) to allow Fuchsia device and emulator traffic.

    This command detects whether an active Linux firewall service is setup,
    and if so, will add special rules to allow Fuchsia-specific traffic to
    go through the link-local IPv6 network interfaces used by Fuchsia devices
    and emulators.

    NOTE: This script uses sudo and will thus ask for your password!

      -n|--dry-run         Just print all steps, don't do any configuration

[setup-ufw source code](https://cs.opensource.google/fuchsia/fuchsia/+/main:tools/devshell/setup-ufw)