BalenaOS iptables rules block forwarding on reboot

## Describe the bug
The host OS blocks IP forwarding by default.

## To Reproduce
1. Deploy lab-tool on a device
2. Reboot the device

## Expected behavior
Forwarding between wifi and ethernet works

## Additional context
This can be worked around while the device is running by executing the following on the host OS:

```bash
iptables -P FORWARD ACCEPT
```
