snoop_logger: Add support for logging to a socket

- Implements writing BTSnoop logs to socket.
- A default socket is registered on start if logs are enabled.
- snoop_logger allows to register a different socket interface
  which overrides the default one.
- This patch allows to see btsnoop logs in Wireshark or btmon
  in real time.
- No need to be root or to disable selinux.
- Wireshark has built-in support for btsnoop logs in Android
  and will detect capture option on startup.
- To enable the feature you need to run: adb shell device_config
  put bluetooth INIT_gd_hal_snoop_logger_socket true
- To use it with btmon: adb forward tcp:8872 tcp:8872 && nc
  localhost 8872 | btmon -P -r /dev/stdin

Test: atest bluetooth_test_gd
Tag: #feature
Bug: 247859568
BYPASS_LONG_LINES_REASON: Bluetooth likes 120 lines

Change-Id: Ia1d3fd8698ef4d2a3bdf92d0c78d20044cfdf96e