When using MdnsSocketClient (unused in the platform, may be used as a
library), allow guessing the Network of incoming packets based on their
source address.
This is flawed as there may be races between LinkProperties updates,
interfaces going up/down, and packets being received, and the source
address can not always be mapped 1:1 to an interface prefix, but it
should improve the situation for legacy code that currently assumes the
Network is the last one that was used for sending, which is often wrong.
Test: atest
Flag: EXEMPT: dead code in Android repo
Change-Id: I885c741d3d40b1b128a06b6d7a7aff8e0551ffea
bdc48fcc63