Draw live tile below Overview after launch animation

A fix (see http://go/b320307512_problems) was put in to change layers
when swiping from Desktop Windowing to Overview, so that the blur effect
 didn't apply to the live tile. The result of this change was that the
 tasks now sat on top of Overview and if you didn't launch the task but
 went back to Overview, then you could interact with them and do things
 like resize the task and get into a very broken state.

This fix simply flips the layer ordering back after the animation
completes to ensure Overview sits on top.

Fix: 373400009
Flag: NONE bugfix
Test: Swipe from Desktop to Overview. Swipe down from Overview to launch
 the live tile, but then swipe back to Overview i.e. don't launch
 Desktop. Try to resize the DW window.

Change-Id: I80c8d72f76a8393eb8bd963df81723defd85ed97
1 file changed