Maybe fix NPE - don't notifyChange if selected visibility is the same

Flag: none / bugfix
Test: none / can't repro
Test: manual - switch between the different radio buttons in bubble settings to make sure they
               all work
Bug: 343167554
Change-Id: I19fc3fa0df59c44e3f22de035c0b377caea1158f

src/com/android/settings/notification/app/BubblePreference.java

@@ -80,8 +80,10 @@ public class BubblePreference extends Preference implements RadioGroup.OnChecked
     }
 
     public void setSelectedVisibility(boolean visible) {
-        mSelectedVisible = visible;
-        notifyChanged();
+        if (mSelectedVisible != visible) {
+            mSelectedVisible = visible;
+            notifyChanged();
+        }
     }
 
     @Override