A brave new world for window insets (5/n)

Implement controlWindowInsetsAnimation

Based on the leashes we have on the client, and the insets the
client has requested, we are able to move the surfaces around
such that the resulting insets will match what the client
requested.

Bug: 118118435
Change-Id: I0616e53455a6544aaf374c1b0eb10e258aced21d