Track window for 2 button nav as well as 0 button

This allows us to revert the change that fades in the shelf during swipe
up in 2 button mode, since the shelf doesn't show up until the window is
out of the way anyway.

Bug: 129746879
Change-Id: I929d8095989f9eae32d71b5bc3f67997e9df4ba0
3 files changed