Don't special case swipe up animation if launcher was visible

This case originally existed to handle transparent activities, but in
reality it was hit most often when swiping up during transitions, i.e.
before launcher was stopped. So now we do the same thing regardless of
whether launcher was "visible" at the start of the animation: go to the
background state immediately and create our transition from there. This
looks a little strange if the activity truly is transparent, because you
can see launcher jump to the background state, but ultimately leads to a
more consistent experience (and the state animation we used before
looked super weird anyway).

Test:
- Open Calculator from the home screen and immediately swipe up from nav
  bar (before animation finishes)
- Open Calculator from overview and immediately swipe up from nav bar
- Open Caluclator from all apps and immediately swipe up from nav bar
- Open Cortana (which has a translucent activity) from home screen,
  then swipe up.
- Open Cortana and quick switch from it
- Open Rube screenshot (dialog activity) from home screen and swipe up
- Open Rube screenshot from all apps and swipe up
- Open Rube screenshot from all apps and swipe up and back down (ensure
  launcher returns to all apps state)

Change-Id: I87bdbc6ddf41971fd327c807269c0bd94c97c95c