Scale snapback velocity by the magnetic multipliers.

When swiping and cancelling a drag on a swiped notificaiton, the
final velocity of the interaction is used to trigger the snap-back
animation for its magnetic neighbors. The velocity is multiplied by the
same magnetic pull factor that controls the translation as notifications
are being dragged. This significantly reduces the wobble observed when
rapidly swiping a notification away.

Test: manual. Verified reduced wobble in neighbor notifications.
Flag: com.android.systemui.magnetic_notification_swipes
Bug: 395893020
Change-Id: I5a7de2734abc708dd85050ce7b38f7a6f7cd5694