Introduce GesturePointerEventListener on sysUI (3/n)

This CL introduces the transient gesture detection logic on the client
side.

The GesturePointerEventHandler is a mirror of existing
SystemGesturesPointerEventListener on the window manager side. The
window manager one can be removed after the entire system UI side logic
is done.

There're some noticible differences, including:
1. GesturePointerEventListener uses system UI side GeneralGestureDetector
   and a bridge class SystemGesturePointerEventListener to receive input
   events.
2. Leave an interface to let the user, the event handler to register a
   callback to receive necessary input events.

Test: build
Test: Enable debug and CLIENT_TRANSIENT flag to observe the log
Bug: 277290737
Change-Id: I13d98303b783dac072d1bd1d06f1b7f0836bf73d