Add InputDispatcher unit tests for untrusted touches [5/n]

This is the unit test compliment of ag/12198106.

Test that taps *inside* windows with flags FLAG_WATCH_OUTSIDE_TOUCH |
FLAG_NOT_TOUCHABLE result in ACTION_OUTSIDE events. This is important
for security to make sure apps can't learn the position of touches
(outside vs inside) while letting them pass-through.

Bug: 158002302
Bug: 177840583
Fix: 110901409
Test: atest InputDispatcherUntrustedTouchesTest
Change-Id: Iaa59fa4c057c2f1d81d0e7010fddf0248adf23e5