[adbwifi] Make AdbManager changes for adb over WiFi.

This CL has a couple of notable changes:
- Add communication layer between adbd, system server, and Settings UI
- Add system notification (Wireless debugging connected) when at least
  one device is connected.
- Add trusted networks (BSSID) to the keystore.
  - Changed the keystore format to:
    <keyStore version="1">
    <adbKey ... />
    <wifiAP ... />
    </keyStore>
 - Currently, trusted networks don't have a expiration time. Also, only
   way to clear it is by blowing up the keystore (revoke permissions).
- Add pairing mechanism:
  - Using libadbwifi_pairing_connection C++ library to pair a device
    using SPAKE2 protocol over TLS.
  - Register MDNS service for client discovery.
- Removed ability to ctl.start/stop adbd from UsbDeviceManager
  - AdbService now controls when to do this

Bug: 111434128, 119490154, 119492574

Test: Manual. From developer options:
1) USB debugging off, WiFi Debugging off
- Ensure both transports are disabled by trying to connect via WiFi and
USB.
2) USB debugging on, WiFi Debugging off
- Connections via USB are available, WiFi is disabled
3) USB debugging off, WiFi Debugging on
- Connections via WiFi are available (IP + port), USB is not available
4) USB debugging on, WiFi Debugging on
- Check both transports work

Change-Id: I9f87679d195da99a55b6faf7131da1f1af65fe01
Merged-In: I9f87679d195da99a55b6faf7131da1f1af65fe01
Exempt-From-Owner-Approval: already approved