Have the stable layout take into account the window's fullscreen flag.

When using stable layouts, you are typically expected to hide and
show the status bar through the system UI fullscreen flag.  This hides
both the status bar and the action bar.  The stable layout assumed
that when not hiding the status bar through the system UI flags, that
the status bar would be visible.

This change makes things a little smarter, also looking at the
window's fullscreen flag (which only hides the status bar).  If this
flag is set on the window, then the stable layout now assumes that
the status bar will never be shown.  This allows us to position the
action bar correctly in the situation where the application has set
the window to fullscreen and requested a stable layout, instead of
always leaving room for the status bar above it.

Change-Id: I757072ae99cd3741753af7210dbf51afe94d3db5