Combine bounds change and move-to-center animations.

Changes the animations for drag to desktop such that the task moves to
the center and changes to default freeform bounds at the same time.

Rather than cutting to the end of the shrink animation, we pause it and
use its current scale and position in the following animation. We then
animate scale to 1 and bounds to the default value.

Video: http://recall/-/epz9aQ1b0dZUySDQa3VwBZ/cTh9tIbYucFflebAPJj0hs
Bug: 315527000
Test: Manual
Change-Id: I46c9f163f42af830fe186c2d9abe030da263eb2f