Enhance BubbleController dumps

- Fix a formatting issue
- Dump Bubble$mIsClearable in BubblesController
  Sometimes when dismissing a Notification which has a Bubble, it gets stuck in the Shade. A possible reason is that we restore the wrong value for this field (false), which blocks us from dismissing it.

Bug: 237897866
Test: adb shell dumpsys activity service com.android.systemui/.SystemUIService WMShell
Change-Id: I38fc1355b4706cab3cf87f415e97f569e2e2ba50

libs/WindowManager/Shell/src/com/android/wm/shell/bubbles/Bubble.java

@@ -870,7 +870,8 @@ public class Bubble implements BubbleViewProvider {
         pw.print("  desiredHeight: "); pw.println(getDesiredHeightString());
         pw.print("  suppressNotif: "); pw.println(shouldSuppressNotification());
         pw.print("  autoExpand:    "); pw.println(shouldAutoExpand());
-        pw.print("  bubbleMetadataFlagListener null: " + (mBubbleMetadataFlagListener == null));
+        pw.print("  isClearable:   "); pw.println(mIsClearable);
+        pw.println("  bubbleMetadataFlagListener null: " + (mBubbleMetadataFlagListener == null));
         if (mExpandedView != null) {
             mExpandedView.dump(pw);
         }