Add dumpsys for bubble state

Test: adb shell dumpsys activity service com.android.systemui | grep -A 50 BubbleController
Change-Id: I33dfd315492870cd9a8d446d714be6a2e5fdf6be
diff --git a/packages/SystemUI/src/com/android/systemui/bubbles/BubbleController.java b/packages/SystemUI/src/com/android/systemui/bubbles/BubbleController.java
index 6e3c410..6e2bcc1 100644
--- a/packages/SystemUI/src/com/android/systemui/bubbles/BubbleController.java
+++ b/packages/SystemUI/src/com/android/systemui/bubbles/BubbleController.java
@@ -81,6 +81,8 @@
 import com.android.systemui.statusbar.policy.ConfigurationController;
 import com.android.systemui.statusbar.policy.ZenModeController;
 
+import java.io.FileDescriptor;
+import java.io.PrintWriter;
 import java.lang.annotation.Retention;
 import java.lang.annotation.Target;
 import java.util.List;
@@ -653,6 +655,15 @@
         return mStackView;
     }
 
+    /**
+     * Description of current bubble state.
+     */
+    public void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
+        pw.println("BubbleController state:");
+        mBubbleData.dump(fd, pw, args);
+        pw.println();
+    }
+
     static String formatBubblesString(List<Bubble> bubbles, Bubble selected) {
         StringBuilder sb = new StringBuilder();
         for (Bubble bubble : bubbles) {