Enable Ethernet tab in data usage

mStateSession is not initialized at the time hasEthernet is called to
set mShowEthernet, so Ethernet tab is not shown at the startup.
In this case, if the device doesn't support mobile network, user cannot
even select it from the context menu.

Bug: 8365419
Change-Id: I441971f18346c34a3adf3f18d9355075d9dce3f0
Signed-off-by: Jaewan Kim<jaewan@google.com>
Settings : Toggle expanded desktop for navbar

If entering the navbar screen with expanded desktop enabled, the navbar
is not shown hence hindering the ability to use the panel

This patchset addresses that by disabling expanded desktop upon entering,
and re-enabling upon exiting if it was previously enabled.

Patchset 2 : Fix state issues

Change-Id: I2776cf971f8899d30a25c0bf6b418793153555fc