Turns out this broke showing the bluetooth menu entry for adapters which
rely on the had-devices-setup property being set while turned off. These
adapters are completely removed from the system by the firmware after
powering them off, so in that case there is no default adapter anymore,
although we still want to show the menu.
This reverts commit aaf47167b5.
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2214>