SystemUI: Internet tile: Allow long-pressing on mobile network

* The current WiFi network has a setting toggle and also opens the
  settings on single click where the mobile network only allows
  connecting but not opening settings
* Add a long press listener that goes to the subId's network settings,
  allowing for example to disable roaming or change network

Change-Id: Iacc1c64d318b0240da5397f2b4e4dfb59d4834dd