[MM] Nudge spring only if there was a jump (discontinuity)

When an unstable motion value reaches a breakpoint with a continuation
function (there is no jump), we should following the target output
rather than adding the velocity.

Screenshot: go/416249374#comment2

Test: atest MotionValueTest
Bug: 416249374
Flag: com.android.systemui.scene_container
Change-Id: Ic5e47365a8ee97b1f49098ec00ccac9263816932
6 files changed