Fixing SysUI reporting expanded split shade state to launcher

Split shade was not registering as being fully expanded as expanded height never reaches full shade height in that state - it reaches only maximum transition distance, so distance of swipe required for shade to fully visually expand.

Fixes: 254044267
Test: NotificationPanelViewControllerTest
Test: adding functional tests in ag/20299906
Change-Id: I734d82f1fc799e63d3fb0b33da780b8df572bc95