Add .local resolution fallback mechanism

RFC6762 specifies that the ".local" suffix is specific to Multicast DNS.
It recommends against using ".local" as a Unicast DNS top-level domain.
However, some network environments still setting up ".local" as Unicast
DNS top-level domain. To better support them, DNS resolver provides a
fallback mechanism to send Unicast DNS queries when Multicast DNS is
failed.

Bug: 221359963
Test: atest
Change-Id: I1b8b20333481c40faf6f9fcbf9884a7545c87b2b