Pointer icon refactor for stylus

When PointerChoreographer is enabled, PointerChoreographer can
create multiple StylusPointerControllers for each stylus device.
A StylusPointerController is created when the corresponding stylus
sends the first hover event. It can show and hide a hover pointer
on the associated display.

Test: atest inputflinger_tests
Bug: 293587049
Change-Id: Iaedf724815d96c3af3accf70dbd54f62b953ecc9