Ensure that stack view exists when applyUpdate

In applyUpdate(), there's a chance that stack view has been removed.
Ensure stack view is created before updating.

fixes: 157778325
fixes: 157944021
Test: atest BubbleControllerTest
Change-Id: I6ff111bf74c11bf44cb8a27260d4dfc04f5d3423

packages/SystemUI/src/com/android/systemui/bubbles/BubbleController.java

@@ -1116,6 +1116,8 @@ public class BubbleController implements ConfigurationController.ConfigurationLi
 
         @Override
         public void applyUpdate(BubbleData.Update update) {
+            ensureStackViewCreated();
+
             // Lazy load overflow bubbles from disk
             loadOverflowBubblesFromDisk();
             // Update bubbles in overflow.