Newly created sandbox in host networking mode has lo interface DOWN

### Description

In our experiment we found that in a newly created gVisor Sandbox, if the network stack is set to none, then there is a lo interface and it is enabled with loopback address of 127.0.0.1. But if the network stack is set to host, the lo interface still exists, but is disabled (i.e. state DOWN). These can all be explained by the code here. https://github.com/google/gvisor/blob/master/runsc/sandbox/network.go#L71

The problem is that in none mode, there is no networking outside of the sandbox. We want to both enable loopback, and also network externally. Is there a way to have lo enabled in host mode?

I have tried to duplicates L60-63 to L72, but it does not work.

### Is this feature related to a specific bug?

_No response_

### Do you have a specific solution in mind?

_No response_