Show dialog when user tries to edit a locked down WiFi config

Also, 'FORGET' button is not shown on WifiDialogs of locked down configs.
Context menu only shows 'Connect' for them.

Bug: 20117316
Change-Id: I3fa986c10b6ff47d1a897794213c225c8c6f579b

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

@@ -315,6 +315,13 @@ public class WifiConfigController implements TextWatcher,
         return (level > -1 && level < mLevels.length) ? mLevels[level] : null;
     }
 
+    void hideForgetButton() {
+        Button forget = mConfigUi.getForgetButton();
+        if (forget == null) return;
+
+        forget.setVisibility(View.GONE);
+    }
+
     void hideSubmitButton() {
         Button submit = mConfigUi.getSubmitButton();
         if (submit == null) return;