Fix the premature hiding of notifications while expanding QS.

This MAY be a fix for an issue where all notifications in the shade disappear, which appears to be caused by getInnerHeight returning the wrong value.  However, I can't repro (or therefore demonstrate the fix works in that case).

Fixes: 188330819
Bug: 191459880
Test: Expand the QS and notice that now the notifications do not disappear.
Change-Id: I21f03dbb162290df540ec23955abe90ee686b696