Add mDNS .local resolution test cases

When testing mDNS IPv4 test cases, they should add routing rules
for MDNS packets, or MDNS packets won't know the destination is
mDNS muticast address "224.0.0.251".For IPv6 test cases, they don't
need to do the same thing.

Bug: 140857615
Test: cd packages/modules/DnsResolver && atest
Change-Id: Iadd724f8917496516db43fd325785caf2b3e31f2