[Wi-Fi] Add object comments for WifiTrackerLib migration

Migrating from Wi-Fi SettingsLib to to WifiTrackerLib, there are
both some Settings files of both version. Developers should
develop on new version files.

Bug: 152571756
Test: compile
Change-Id: I4446e2e333663bf69daa1ceff102775889021851

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

@@ -22,6 +22,9 @@ import android.widget.Button;
 
 /**
  * Foundation interface glues between Activities and UIs like {@link WifiDialog}.
+ *
+ * Migrating from Wi-Fi SettingsLib to to WifiTrackerLib, this object will be removed in the near
+ * future, please develop in {@link WifiConfigUiBase2}.
  */
 public interface WifiConfigUiBase {
 
@@ -56,4 +59,4 @@ public interface WifiConfigUiBase {
     public Button getSubmitButton();
     public Button getForgetButton();
     public Button getCancelButton();
-}
+}