Display network name in status bar

When config_showOperatorNameInStatusBar is true, "Network name" setting
is displayed in Settings app (Settings > Display).
The user can turn on/off the feature to display the network name in the
status bar from Settings app.

Fixes: 67620513
Test: manual - go to Settings > Display and turn on/off Network name.

Change-Id: I43f1d9cbea363527250639ce6146f1c5c6c8a482