Implement Stylus Prediction Metrics

Fills out the implementation and tests for MotionPredictorMetricsManager.

(main cherry pick: ag/24451072)

Test: atest frameworks/native/libs/input/tests/MotionPredictorMetricsManager_test.cpp
Test: Manual testing on-device, computed metric values seem reasonable.

Bug: 268245099

Merged-In: Iec18415de9c3070f2b285c5c82f5a5e0ceaaf471
Change-Id: I0def0dae626adbbe33e1ed90c08b2cae867cde01