iptables: don't pollute logs
iptables: don't pollute logs

The netfilter package uses logs to make debugging the (de)serialization of
structs easier. This generates a lot of (usually irrelevant) logs. Logging is
now hidden behind a debug flag.

PiperOrigin-RevId: 309087115

google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor