Add stack/animation controller dumpsys.

Test: adb shell dumpsys activity service com.android.systemui | grep -A 100 BubbleController
Change-Id: I6fb09422930066cafe9811e2840f0b631f4c1b05
diff --git a/packages/SystemUI/src/com/android/systemui/bubbles/BubbleController.java b/packages/SystemUI/src/com/android/systemui/bubbles/BubbleController.java
index 6e2bcc1..51ba968 100644
--- a/packages/SystemUI/src/com/android/systemui/bubbles/BubbleController.java
+++ b/packages/SystemUI/src/com/android/systemui/bubbles/BubbleController.java
@@ -662,6 +662,10 @@
         pw.println("BubbleController state:");
         mBubbleData.dump(fd, pw, args);
         pw.println();
+        if (mStackView != null) {
+            mStackView.dump(fd, pw, args);
+        }
+        pw.println();
     }
 
     static String formatBubblesString(List<Bubble> bubbles, Bubble selected) {