Fix issues with landscape transition

Bug: 158675544
Bug: 158675318
Test: manual - rotate phone to landscape, with stack expanded /
collapsed-then-expanded, select bubbles and overflow,  see that
        Overflow height matches normal bubble activity
        Expanded view at correct location and size
        Pointer still points to correct bubble
        Bubble spacing is wider as intended

Change-Id: I32bf1cdeaa4bade4d806e04b423f56991b41c3be