Enable "localfilesystem" UNIX domain socket for ADB.

This patch introduce "service.adb.listen_addrs", a new
string type property, while keeping the old properties.
The new property added in this patch is used to listen
on UNIX domain socket "localfilesystem".

"service.adb.listen_addrs" can be used to listen on
multiple addresses, such as tcp:5555 and tcp:5556.
It is separated by ',' (comma) character.

In the process of introducing the new socket type, the
method tcp_connect is removed and combined into
socket_spec_connect.

Without specifying using the new property, adb will
try to listen on both tcp and vsock (following the
previous implementation).

Some examples of the new property value are:
  - "tcp:5555"
  - "vsock:5555"
  - "localfilesystem:/tmp/test"
  - "tcp:5555,vsock:5555"

Bug: 133378083
Test: On master-arc-dev:
        adb root;
        setprop service.adb.listen_addrs localfilesystem:
	    <path_to_socket>;
        adb connect localfilesystem:<path_to_socket>;
        adb -s localfilesystem:<path_to_socket> shell;
	    inside Chrome OS.
Test: On aosp_bluefin:
        setprop service.adb.listen_addr tcp:5555;
        adb connect <IP>:5555; adb shell;
Test: On aosp_bluefin:
        setprop service.adb.tcp.port 5555;
        adb connect <IP>:5555; adb shell;
Test: On aosp_bluefin:
        setprop service.adb.listen_addrs tcp:5555,tcp:6666;
        adb connect <IP>:5555; adb shell;
        adb connect <IP>:6666; adb shell;
Test: On aosp_bluefin:
        ./adb_test;
Test: On cuttlefish:
        launch_cvd;
        adb -s 127.0.0.1:6520 shell;
Test: Ran host tests:
        ./adb_test;
        ./adb_integration_test_adb;
        ./adb_integration_test_device;

Change-Id: I8289bf0ab3305cf23ce5695ffba46845d58ef6bb