Fix the end-icon missing issue for Wi-Fi networks

- Because WifiEntryPreference needs to support policy transparency, the inherited class is changed from Preference to RestrictedPreference.

- The RestrictedPreference will hides the end icon as default, causing this issue to happen.

- Override the getSecondTargetResId() function with necessary resource id to avoid the end-icon being hidden.

- Remove the redundant setWidgetLayoutResource, because it will be initialized in the extended class.

Bug: 262456749
Test: manual test
make RunSettingsRoboTests ROBOTEST_FILTER=WifiEntryPreferenceTest

Change-Id: Ie3d3a649d3137dc705d7887c8e74592437d9ce61

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

@@ -82,7 +82,6 @@ public class WifiEntryPreference extends RestrictedPreference implements
         super(context);
 
         setLayoutResource(R.layout.preference_access_point);
-        setWidgetLayoutResource(R.layout.access_point_friction_widget);
         mFrictionSld = getFrictionStateListDrawable();
         mWifiEntry = wifiEntry;
         mWifiEntry.setListener(this);
@@ -280,6 +279,11 @@ public class WifiEntryPreference extends RestrictedPreference implements
         notifyChanged();
     }
 
+    @Override
+    protected int getSecondTargetResId() {
+        return R.layout.access_point_friction_widget;
+    }
+
     @Override
     public void onClick(View view) {
         if (view.getId() == R.id.icon_button) {