Fix carrier-specific Wi-Fi settings appears in search - even on non-carrier phone

The preference should be removed from the search result when
the availability status is false.

Change-Id: I979bc70ec7672b137b96a7e02db2e9ba29fbb7a8
Fixes: 112550245
Test: manual and robotests

src/com/android/settings/wifi/ConfigureWifiSettings.java

@@ -85,7 +85,6 @@ public class ConfigureWifiSettings extends DashboardFragment {
         controllers.add(mUseOpenWifiPreferenceController);
         controllers.add(new WifiInfoPreferenceController(context, getSettingsLifecycle(),
                 wifiManager));
-        controllers.add(new CellularFallbackPreferenceController(context));
         controllers.add(new WifiP2pPreferenceController(context, getSettingsLifecycle(),
                 wifiManager));
         return controllers;