Fix issue with split thumbnails overflowing during rotation

Fixes a set of issues in Overview where you could cause split thumbnails to overflow their contents into each other by rotating the phone in certain ways.

The issue occurred because StagedSplitBounds objects have their height and width assigned differently depending on if they were created while the phone was in portrait or landscape.

Fixed by adding a conditional check in PortraitPagedViewHandler#setSplitTaskSwipeRect and LandscapePagedViewHandler#setSplitTaskSwipeRect.

Fixes: 218784856
Fixes: 218779313

Test: Manual on local devices
Change-Id: I04b4f4344250da34616ab1744af22fa41b9aba9b