Support showTouches on multi-display (2/2)

Currently the PointerController would be associated with the top most
freeform or external display if enable desktop mode.
But for presenting spots when enable showTouches from develop options,
they should be shown on the corresponding display where user touched.

Also changed Vector to std::vector.

Test: atest inputflinger_tests
Test: Use device support multi-display and touch screen (like mojave).
      Enable showTaps from develop options and check if show tap spots.
Bug: 120815589

Change-Id: I0854fa97813aabf005dccb8ec6fbda10106126e9