[Floaty] Assistant haptics independent of invocation effect

This changes satisfies the logic behavior outlined in the table of:
https://b.corp.google.com/issues/417145104#comment6

This better separates the previous assistant haptics from the invocation
effect haptics.

Test: manual. Verified the correct haptics play according to the various
  combinations of the LPP invocation effect and LPP haptics flags (see the
  table in the buganizer comment above)
Flag: com.android.systemui.shared.enable_lpp_assist_invocation_haptic_effect
Bug: 417145104

Change-Id: I5676675b424e1a96b2e0c5d8cfb2878f246fbd1d