Implement new design of Wi-Fi card

- always show Wi-Fi card
- collapse the card in the new UI session when connecting to a stable
  network
- hide toggle, show a level icon and subtext in the new collapsed mode
- show loading row when the AP list is not full

Test: robotest
Fixes: 147473096
Change-Id: I893064ef04d40d8e7cb8e62c1e72a2cb5e97f6ac

src/com/android/settings/wifi/slice/ContextualWifiScanWorker.java

@@ -62,4 +62,9 @@ public class ContextualWifiScanWorker extends WifiScanWorker {
         }
         return true;
     }
+
+    @Override
+    protected int getApRowCount() {
+        return ContextualWifiSlice.getApRowCount();
+    }
 }