Add native MotionPredictor

The native MotionPredictor will call neural net code to create motion
predictions for the provided gesture stream.

In this CL, a simple linear extrapolation model is provided in order to
test the API.

To enable prediction:
adb shell setprop persist.input.enable_motion_prediction true

Bug: 167946763
Test: atest InputTests inputflinger_tests libinput_tests
Change-Id: Id8a23b728aeb844288d5b8daae0829d61d4c1482