Fix taskbar stash misalignment when going from app to overview

Keep taskbar unaligned with hotseat if we're stashing anyway

Test: Swipe up from app with taskbar present to overview, check frame by frame to ensure icons morph directly into the handle instead of above it
Fixes: 208697792
Change-Id: If3238286b3383e75eb71fbd3b97d34bb3b44340b