In the test below it only expects MockSprite#setIcon() being called
once, but with animation it may be called multiple times.
Bug: 144947344
Test: atest PoitnerControllerTest#updatePointerIcon
Change-Id: I5c4908fb8301cae144fd637c831f2012a35862e3
Also bootstrap unit tests for PointerController. Need to mark 3
functions of SpriteController virtual so their behaviors can be
overridden.
Bug: 130822623
Test: SurfaceFlinger can get cursor type and hotspot.
Change-Id: I739cd03214364144bb4e22a166ecc7abfd3492fe