Whitelist fragments appropriate for an activity

Change-Id: If4f8c4e9d9949b652946cffe0ebb09b587e5a042

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

@@ -16,6 +16,7 @@
 package com.android.settings.wifi;
 
 import com.android.settings.ButtonBarHandler;
+import com.android.settings.ChooseLockGeneric.ChooseLockGenericFragment;
 
 import android.app.Fragment;
 import android.content.Intent;
@@ -42,6 +43,12 @@ public class WifiPickerActivity extends PreferenceActivity implements ButtonBarH
         return modIntent;
     }
 
+    @Override
+    protected boolean isValidFragment(String fragmentName) {
+        if (WifiSettings.class.getName().equals(fragmentName)) return true;
+        return false;
+    }
+
     /**
      * Almost dead copy of
      * {@link PreferenceActivity#startWithFragment(String, Bundle, Fragment, int)}, except