Fix some config issues with sysui

It wasn't creating a delta so as soon as a change happened, it would
return true for any config changes.

Also StatusBar wasn't receiving config changes because the callback
was named wrong and SystemBars no longer passes it through.

Test: manual
Fixes: 62968485
Fixes: 62893293
Change-Id: I56750047168007edd0ca9ea35cb36c23dc790661