Support multiple IPv4 / IPv6 addresses in MdnsResponse

If the mDNS service has multiple IPv4 / IPv6 addresses, only the
last added address will be present on the response. Since the
NsdServiceInfo supports multiple host addresses in Android U, the
MdnsResponse should also support multiple IPv4 / IPv6 addresses
in favor of providing accurate service info to clients.

Check cache flush flag on the response when adding a new address
record. Per RFC6762 10.2, clear all address records if the
cache-flush bit set.

Bug: 268586836
Test: atest FrameworksNetTests
Change-Id: I04548a3f16837939f3131b84c1033377ff81d521