PointerChoreographer: Support drawing tablets that report mouse events

It appears that emulators use an input device that we treat as a drawing
tablet to report abosulte mouse coordinates. That means it's possible
for drawing tablets to report mouse events, so make our code receptive
to this situation.

Bug: 330701458
Test: atest inputflinger_tests
Change-Id: I21cfa1070ab410c5c677534b2843418b58b8822e