The topmost notification is now not collapsed anymore but slides in
expanded from the top. Therefore it's layout doesn't need to animate
anymore. This also cleans up a lot of code in the algorithm which was
depending on this resizing which isn't needed anymore.
In order to have that transition working perfectly, the padding when
collapsing a card is now the same as the slowdown length.
Also improved the logic when notification contents are allowed to
animate and when not.
Also fixed a bug where the top notification was cut off when QS was
expanded.
Bug: 27402534
Bug: 18434284
Change-Id: I31afa199d38d94e74fd45500c2236ffdb51d989d
d1ad9ab312