Add TFLite model for motion prediction.

This model generates probabilistic motion predictions based on a
sequence of relative input movements. The input movements are converted
into polar coordinates (distance and angle) based on an axis that
follows the current path. This ensures that the orientation of the
device and of the inputs do not affect the predictions. The orientation
of the input device is also transformed to be relative to the path axis.

The test cases verifying model efficacy are consolidated into CTS.

Bug: 167946763
Test: atest libinput_tests
PiperOrigin-RevId: 492068340
Change-Id: Icd8d90bd5a7ce79c699bfdb6367a4cbd8130441a