Cleanup/consolidate normal<->all apps interpolators

We no longer need to have a different behavior for no button mode,
so make PortraitStatesTouchController the source of truth

Also remove unused ANIM_ALL_APPS_HEADER_FADE & RECENTS_FADE_THRESHOLD

Test: manually in 0 button and 3 button modes
Bug: 183001675
Bug: 175137718
Change-Id: If0bc2a6d6d3bf1649fad45226a4e6055f30e4880