Bridge: the isolation option disappears after reboot
To reproduce
Add a bridge and reboot the router
```
set interfaces ethernet eth1 vif 21
set interfaces ethernet eth1 vif 22
set interfaces bridge br1 member interface eth1.21 isolated
set interfaces bridge br1 member interface eth1.22 isolated
```
Check before reboot:
```
vyos@r1# bridge --json -d link | jq '.[] | {ifname, isolated}'
{
"ifname": "eth1.21",
"isolated": true
}
{
"ifname": "eth1.22",
"isolated": true
}
```
Reboot the router and check again:
```
vyos@r1:~$ bridge --json -d link | jq '.[] | {ifname, isolated}'
{
"ifname": "eth1.21",
"isolated": false
}
{
"ifname": "eth1.22",
"isolated": false
}
```
Prio:
```
vyos@r1:~$ /usr/libexec/vyos/priority.py | match "vif|_bridge|_ether"
310 interfaces_bridge.py ['interfaces', 'bridge']
318 interfaces_ethernet.py ['interfaces', 'ethernet']
vyos@r1:~$
```