Ignore traffic from cache-local SSL terminators

Webstatscollector's C implementation also ignores traffic from
  10.20.0.0/24
  10.64.0.0/24
  10.64.32.0/24
since Ic6e1f8e6f58091b2274a3ab45ddfe38bc9489591.

In order to make them agree again, we also ignore traffic from those
nets.

Bug: T76390
Change-Id: I3ef0ef2a6bdd16c7f00f56216df47b18df2aa9df