Two parts to this:
1. We were looking at the measured height of the close view
for a lot of our computations, which---particularly with
recent changes that dispense with the old 3-window
implementation---is increasingly unreliable
2. We were overestimating the minY that the panel must be
pulled down before animation starts. It was enforced
jankiness!
Bug: 5359178
Change-Id: Ie09b62226b7b0977527348b5527478665ece1df8
1fac1fdd79