This change makes it so that PointerController does not ask its Policy
to load any resources for any displays until a DisplayViewport is set,
and verifies this with unit tests.
Bug: 145699789
Bug: 146385350
Test: atest libinputservice_test
Change-Id: I2e48e7ac4700e6f9fdf939a7bd0e6639b051ade6
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
