System UI keeps stopping when dismiss the bubble

[huynguyennovem]

I got crash by following these steps:

1. Click to Sheep
2. Click Open Bubble chat by clicking on action bar menu icon
3. Wait for incoming chat via bubble
4. Click on bubble chat
5. Drag bubble to X (close) area

Crash content:

2020-07-16 17:59:22.848 21078-21078/? E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.android.systemui, PID: 21078
    java.lang.NullPointerException: Attempt to invoke virtual method 'void com.android.systemui.bubbles.BubbleStackView.setSelectedBubble(com.android.systemui.bubbles.BubbleViewProvider)' on a null object reference
        at com.android.systemui.bubbles.BubbleController$9.applyUpdate(BubbleController.java:1266)
        at com.android.systemui.bubbles.BubbleData.dispatchPendingChanges(BubbleData.java:503)
        at com.android.systemui.bubbles.BubbleData.notificationEntryRemoved(BubbleData.java:297)
        at com.android.systemui.bubbles.BubbleStackView.dismissBubbleIfExists(BubbleStackView.java:2088)
        at com.android.systemui.bubbles.BubbleStackView.dismissMagnetizedObject(BubbleStackView.java:2080)
        at com.android.systemui.bubbles.BubbleStackView.access$800(BubbleStackView.java:115)
        at com.android.systemui.bubbles.BubbleStackView$4.lambda$onReleasedInTarget$0(BubbleStackView.java:425)
        at com.android.systemui.bubbles.-$$Lambda$BubbleStackView$4$aSvR9-6CLWJ5wWFJfNBEMIcwA5g.run(Unknown Source:2)
        at com.android.systemui.bubbles.animation.PhysicsAnimationLayout$PhysicsPropertyAnimator$4.onAnimationEnd(PhysicsAnimationLayout.java:998)
        at androidx.dynamicanimation.animation.DynamicAnimation.endAnimationInternal(DynamicAnimation.java:695)
        at androidx.dynamicanimation.animation.DynamicAnimation.doAnimationFrame(DynamicAnimation.java:670)
        at androidx.dynamicanimation.animation.AnimationHandler.doAnimationFrame(AnimationHandler.java:158)
        at androidx.dynamicanimation.animation.AnimationHandler$AnimationCallbackDispatcher.dispatchAnimationFrame(AnimationHandler.java:61)
        at androidx.dynamicanimation.animation.AnimationHandler$FrameCallbackProvider16$1.doFrame(AnimationHandler.java:207)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:970)
        at android.view.Choreographer.doCallbacks(Choreographer.java:796)
        at android.view.Choreographer.doFrame(Choreographer.java:727)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:957)
        at android.os.Handler.handleCallback(Handler.java:938)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:223)
        at android.app.ActivityThread.main(ActivityThread.java:7656)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)