Let InputReader set mouse cursor's display.

InputReader was already responsible to bind device/event and display. It
makes sense to further extend it to control the display where mouse
cursor is shown.

Bug: 146385350
Test: Mouse cursor shows up at expected display.
Test: atest inputflinger_tests
Change-Id: Ie7a9546550b70c8834462b06de929472196fe713
Merged-In: Ie7a9546550b70c8834462b06de929472196fe713