bearer-mbim: don't fail IPv4 connection if IPv4v6 was requested
If we ask for IPv4v6 is requested but the network only grants IPv4, we end up receiving the 'Connect Set' response with nw_error set to 'pdp-type-ipv4-only-allowed'. In this case, we should still succeed the connection attempt and only report the IPv4 info.
We therefore change the logic to skip processing the nw_error unless the activation state is reported as ACTIVATED or ACTIVATING.