Show icon and network label when using Wifi.

+ Add Wifi icon and network label, to be shown when CAPABILITY_WIFI
is present on the primary call. Assume we can infer the network label
from the connection info returned by the WifiManager, supposing that
the phone can only be connected to one wifi network.
+ Add helper to strip quotation marks from wifi network name.
+ Reposition HD audio icon beneath the name, and to the left of the
number/location information.
+ Adjust assets and layout of call state and hd audio icons, to
center them in a more visually pleasing way in the view.

Bug: 19151850
Change-Id: Ic23d1e744960e80b65bc34a8e709266af508fe21