The status bar now extends behind the nav bar, and uses
fitsSystemWindows to ensure its content is not covered. We
always report a stable content insets (as if the nav bar is
visible) even if the nav bar is hidden, so the content doesn't
jump when transitioing. This does mean that if you only hide
the nav bar (and not the status bar), when in landscape you
will end up with a status bar whose right side still leaves
room for the nav bar. But why the hell would you want to do
that?
Also improve documentation on setSystemUiVisibility().
Change-Id: I8087d875f1214ef0085a91b5ed5c2f35ff2fc1b3
9801435820