SystemUI: update nav bar keyguard logic

More consistant with statusbar transparency logic.

Change-Id: Ieba5e695417f2c0a7e34805a21c7b198274ccf83
Signed-off-by: Roman Birg <romanbirg@gmail.com>
derp
SystemUI: fix GPS toggle not changing states properly

When turning GPS on/off from outside the toggles (ie Settings),
it would not send updates to the callback implementations.

Change-Id: Ie462a9a160f8e262980bcf326685392546aee1ee
Signed-off-by: Roman Birg <romanbirg@gmail.com>