Not sure why I can't mark your response as the right answer to this topic to mark it as completed but I guess that's because I haven't really bound this email to this google group and I made the mistake of posting with this email instead of my actual account.
In any case, thank you for your response. I figured it out myself that it was added immediately after configuring sys-usb vm on the initial selection presented to the user on first-time boot of Qubes OS. -- You received this message because you are subscribed to the Google Groups "qubes-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to qubes-users+unsubscr...@googlegroups.com. To post to this group, send email to qubes-users@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/qubes-users/c72a961c-68a2-42b2-a23c-7fe42708429d%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.