[adbwifi] Add adbwifi_libs, TLS connection, and MDNS implementation.

Bug: 111434128, 119493510, 119494503

Test: Enable wireless debugging in Settings UI, click "pair with pairing code"
to generate pairing code.
On client, 'adb pair <ip_address>', enter pairing code at prompt and hit
enter. Pairing should complete.
'adb logcat'.
Change-Id: I86527bd3fc52e30a8e08ec5843dc3e100abf91fa
Exempt-From-Owner-Approval: approved already