Adds 'flinging-then-springing' to the PhysicsAnimator.

See http://go/physics-animator-design#heading=h.ib2uxhal5wrq and http://go/physics-animator-design#heading=h.fu8468xbcwxo

Test: atest SystemUITests
Change-Id: I55b0db822c9468de239dc5d2aa9fa080ad7131ab
3 files changed