Add private dns dialog in wifi settings

This option lives in menu. A dialog will show up once this menu
is clicked.

We reuse most of the logic in go/aog/524415 with the following
updates:
1. Use radioGroup instead of directly control radioButton
2. remove bunch of methods if they are only used once.

Following cl will:
1. Remove this feature in development page
2. Add the help link at the bottom of the dialog
3. Disable "Save" button when hostname is invalid.

Bug: 68030013
Test: add for later

Change-Id: I4c6d359dc9c55675858c20e47953ef677b31c3b5

src/com/android/settings/network/NetworkDashboardFragment.java

@@ -48,8 +48,11 @@ public class NetworkDashboardFragment extends DashboardFragment implements
         MobilePlanPreferenceHost {
 
     private static final String TAG = "NetworkDashboardFrag";
+    private static final int MENU_NETWORK_RESET = Menu.FIRST;
+    private static final int MENU_PRIVATE_DNS = Menu.FIRST + 1;
 
     private NetworkResetActionMenuController mNetworkResetController;
+    private PrivateDnsMenuController mPrivateDnsMenuController;
 
     @Override
     public int getMetricsCategory() {
@@ -69,7 +72,9 @@ public class NetworkDashboardFragment extends DashboardFragment implements
     @Override
     public void onAttach(Context context) {
         super.onAttach(context);
-        mNetworkResetController = new NetworkResetActionMenuController(context);
+        mNetworkResetController = new NetworkResetActionMenuController(context, MENU_NETWORK_RESET);
+        mPrivateDnsMenuController = new PrivateDnsMenuController(getFragmentManager(),
+                MENU_PRIVATE_DNS);
     }
 
     @Override
@@ -81,6 +86,7 @@ public class NetworkDashboardFragment extends DashboardFragment implements
     public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
         super.onCreateOptionsMenu(menu, inflater);
         mNetworkResetController.buildMenuItem(menu);
+        mPrivateDnsMenuController.buildMenuItem(menu);
     }
 
     @Override