Fix NPE in ConnectivityService

Could occur when requestRouteToHostAddress is called on a network
with no associated tracker.  Code later in the method handles
this case gracefully but code introduced in JB throws an exception.

Change-Id: I6c8a0e313ecbcca120aeb5dd0802a72114749aa1
Fix navbar layout

Before: http://owain.nl/before.png
After:  http://owain.nl/after.png

Change-Id: Ie3e3c54a9644d232b1d9b74cbc9fa0eeed072b98
Updated drawables for navbar

Replaced old icons with edited and centered kitkat ones.

Change-Id: I9d996c19763c6e46c5495e790955a35f65cdfde9
Signed-off-by: kecinzer <kecinzer@gmail.com>
SystemUI: update custom nav bar icons

Give them a drop shadow like the new buttons

Change-Id: Iff7d0b1230e824925c98faba99f1a0daa07f0dd4
Signed-off-by: Roman Birg <romanbirg@gmail.com>