Fix clipping issue when dragging app pair icons

This CL changes AppPairIcon#getWorkspaceVisualDragBounds() to return the correct icon bounds, fixing an issue where the icon would appear clipped when being dragged.

Fixes: 312299947
Test: Icon is no longer clipped while dragging
Flag: ACONFIG com.android.wm.shell.enable_app_pairs DEVELOPMENT
Change-Id: I103bdf53bf34d751147e1ba892f36145f04175e4