Unconnected bluetooth devices in vicinity show up in network list

Reference: https://gitlab.gnome.org/GNOME/gnome-shell/issues/507

I noticed that nearby devices (of whose I have no idea) are showing up in my network device list as if they were part of my computer. Not totally sure where the end-point of the issue lies (bluetooth, NetworkManager, etc), but figured I'd file here based on Bastien's comment on the other bug.