rules: move builtin calls before the permissions section

<heftig> kay: systemd commit 22582bb broke cups usb printing for me
<heftig> because the "lp" group isn't applied anymore
<heftig> SUBSYSTEM=="usb", ENV{DEVTYPE}=="usb_device", ENV{ID_USB_INTERFACES}=="*:0701??:*", GROUP="lp"
<heftig> moving this line to the end of 50-udev-default.rules restores correct behavior, as it's after usb_id