Fix entry bounds for 3 button nav

The fix uses the similar approach to shelf height to ensure that the
keep clear area is being updated as soon as possible for quickstep.

Without this, the entry animation finishes before the actual keep
clear area from the view is registered, which causes the PiP to enter
lower right corner and then move up, which was the regression.

Bug: 260779127
Test: manually
Test: http://recall/-/g8x7ZkgdfbqscttAA9wzl9/72aNHwWH5wihwN4gf3mfj

Change-Id: Ide11a903558d7e6cb9e477abe12b81129a7f7afc