[flexiglass] Pin bouncer UX polish.

This aligns the implementation closer to the go/android-u-bouncer-motion spec

- adds haptic feedback on pin touch
- updates colors to better match spec (but not all color tokens are available in code yet)
- update animation easing and durations to match spec
- add a hold time to short button presses.

Bug: 282730134
Test: Manual verification. Please see video capture attached to b/282730134.

Change-Id: Icdf24c17666fb85b0e7c7d28f1d46cb903cfe54c