Revert "Expose startedPosition and pointersDown to NestedScrollHandler"

This reverts commit 9a42e828b01f90d84c5a99daf89bd71b955621f6.

Reason for revert: Bug in STL transition

Test: no test
Bug: 330200163
Flag: com.android.systemui.scene_container
Change-Id: I4319ad2138d7e4e958733e6610eb1ac26f701a06
4 files changed