Add the confirmation dialog when user disable mobile data at first time

Bug: 189983549
Test: atest ProviderModelSliceTest
Change-Id: I83fcadb07e4f8dff5d07bc4015c0c6004c4f5de5

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

@@ -264,7 +264,7 @@ public class ProviderModelSliceHelper {
         return summary;
     }
 
-    private String getMobileTitle() {
+    protected String getMobileTitle() {
         String title = mContext.getText(R.string.mobile_data_settings_title).toString();
         if (mSubscriptionManager == null) {
             return title;