Ensure drag-and-drop and pilfering does not work with hovering pointers

There was a bug where TouchedWindow::getTouchingDeviceIds() would return
a list of all "active" devices (hovering or touching) instead of just
touching.

Fix that bug to ensure there is no crash when trying to start
drag-and-drop with a hovering pointer. Add tests to verify.

Bug: 312636191
Test: atest inputflinger_tests
Change-Id: I865582f21fbe34aca9c1274b02d002018bc9c149