Add cilium_enable_l7_proxy and cilium_tofqdns_min_ttl variables

[mcolmant]

What would you like to be added

I would like to add 2 variables: cilium_enable_l7_proxy and cilium_tofqdns_min_ttl to enabled DNS based Cilium Network Policies (https://docs.cilium.io/en/latest/security/policy/language/#dns-based). These are the minimal set of variables required to make it work correctly.

Why is this needed

It's needed to enable the use of DNS based Cilium Network Policies.