SystemUI: properly adjust statusbar height on rotate as necessary

Some devices may want a different statusbar height between landscape and
portrait.

For this to work, we need to read the statusbar height from the internal
framework where the statusbar height overlay happens.

Change-Id: I34b5549fee5e3fe7c4810dfecb66087e28b01d74
Signed-off-by: Roman Birg <romanbirg@gmail.com>