BubbleData [5/n]: Split up StackView.setExpandedBubble

This splits setSelectedBubble into two discrete steps,
setSelectedBubble, and setExpanded. These will allow
BubbleData to dispatch these actions independently.

Bug: 123542488
Test: atest BubbleControllerTest
Change-Id: I7393d06b08713dc966acd96e165d32ff1e8110f3
diff --git a/packages/SystemUI/src/com/android/systemui/bubbles/BubbleController.java b/packages/SystemUI/src/com/android/systemui/bubbles/BubbleController.java
index 418d052..dfa9c95 100644
--- a/packages/SystemUI/src/com/android/systemui/bubbles/BubbleController.java
+++ b/packages/SystemUI/src/com/android/systemui/bubbles/BubbleController.java
@@ -356,8 +356,10 @@
             ensureStackViewCreated();
             mStackView.addBubble(notif);
         }
+        Bubble bubble = mBubbleData.getBubble(notif.key);
         if (shouldAutoExpand(notif)) {
-            mStackView.setExpandedBubble(notif);
+            mStackView.setSelectedBubble(bubble);
+            mStackView.setExpanded(true);
         }
         updateVisibility();
     }