MotionEvent: Round coordinates to a precision of 0.001

When tests inject input events at a location on the screen, the
dispatched event is expected to have the same coordinates. However, on
scaled devices, this may not always be the case due to precision losses
incurred through floating point arithmetics. For example, it was
possible for an injected event with a coordinate of 1.0 to end up with
a value of 0.9997.

To combat this issue, we will round transformed axis values that are
leaving a MotionEvent to a precision of 0.001. After this CL, even if
the injection process results in precision losses, they should be
overcome by rounding, assuming injection does not require greater
precision.

This will solve the issue where input injected to an inclusive edge of
the View bounds was not getting dispatched to the View due to precision
losses.

Bug: 264978231
Bug: 260965930
Test: atest libinput_tests
Test: atest inputflinger_tests
Test: atest HoverTest (with screen size override)
Change-Id: I81062597058361a1218e6873d34b9b0d2fbfad96