WireGuard Android: Cached resolved host

[Jason A. Donenfeld]

t's mostly this way to prevent DNS lookup failures during the network
connectivity changes, such as turning on and off and on a tunnel
really fast. I agree the current implementation's behavior is
suboptimal though. Probably instead we should invalidate based on the
TTL.

The code in question lives at
app/src/main/java/com/wireguard/config/InetEndpoint.java if you want
to take a stab at fixing it.