Fix NPE for the Enable Nav Ring commit.

Our updateSettings was different from AOKP's and was causing a NPE. To
fix that, I had to create a new function called updateNavBar.

Change-Id: Ia822a7473de7b24b0dcd6912464df2d325ac5d41
Signed-off-by: Lokesh Chamane <lokesh.c703@gmail.com>