firewall: filter net devices using a bitmask &
firewall: filter net devices using a bitmask &

Check the device's capability using & as some devices capabilities are
of value 11 which makes it show up twice.

Closes #17280

cockpit-project/cockpit,mvollmer/cockpit,cockpit-project/cockpit,cockpit-project/cockpit,martinpitt/cockpit,martinpitt/cockpit,martinpitt/cockpit,mvollmer/cockpit,mvollmer/cockpit,martinpitt/cockpit,cockpit-project/cockpit,mvollmer/cockpit,mvollmer/cockpit,cockpit-project/cockpit,martinpitt/cockpit