Merge changes I0ab00c03,Ib4e83e36,I72b17568,If4ea3575,If63bf25f, ... into ub-launcher3-qt-dev

* changes:
  Clear all button should not be swipable
  Use custom drawable for Recents Go thumbnails (1/2)
  Add clear all view that scales off device height
  Ensure recents scrolled to first task in landscape
  Enable landscape mode for Recents Go.
  Remove old recyclerview layout logic
  Calculate task height directly off portrait height
  Fix task adapter notify merge conflict
  Move clear all to recycler view (2/2)
  Move clear all to recycler view (1/2)
  Only switch item animator on content fill if needed
  Fix NPE and make getTask return Optional
  Fix ViewTreeObserver crash on Recents Go
  Fix snapshots not updating on app => overview.
  Fix views not being visible on Recents Go.
  Smarter task laying out based off onMeasure
  Change layout size to be dependent on device size
  Update Go recents visibility based off adapter
  Animate content fill animation to Recents Go
  Animate to bottom view in app => overview
  Differentiate empty UI from default in recents Go
  Add task content animation property
  Fix transition progress not applying to drawables
  Change layout anim from Animation => Animator
  Add drawable for default thumbnail for Recents Go