Unable to make Chat bubbles in Android 11

Question

The Helper class I picked from the official android documentation. Is there anything I am missing that prevents the bubble from appearing?

@RequiresApi(Build.VERSION_CODES.Q)
class NotificationHelper(private val context: Context, val shortcutId: String) {

    companion object {
        /**
         * The notification channel for messages. This is used for showing Bubbles.
         */
        private const val CHANNEL_NEW_MESSAGES = "new_messages"

        private const val REQUEST_CONTENT = 1
        private const val REQUEST_BUBBLE = 2
    }

    private val notificationManager: NotificationManager =
            context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager

    private val shortcutManager: ShortcutManager =
            context.getSystemService(Context.SHORTCUT_SERVICE) as ShortcutManager

    private fun setUpNotificationChannels() {
        if (notificationManager.getNotificationChannel(CHANNEL_NEW_MESSAGES) == null) {
            notificationManager.createNotificationChannel(
                    NotificationChannel(
                            CHANNEL_NEW_MESSAGES,
                            context.getString(R.string.title_float),
                            NotificationManager.IMPORTANCE_HIGH
                    ).apply {
                        description = context.getString(R.string.description_float)
                        setAllowBubbles(true)
                        lockscreenVisibility = NotificationCompat.VISIBILITY_PUBLIC
                    }
            )
        }
        updateShortcuts()
    }

    private fun getPerson(): Person {
        return Person.Builder()
                .setIcon(IconCompat.createWithResource(context, R.drawable.silhouette))
                .setName(context.getString(R.string.app_name))
                .setKey(context.getString(R.string.app_name))
                .setImportant(true)
                .build()
    }

    @WorkerThread
    fun updateShortcuts(): ShortcutInfoCompat {
        // Create a dynamic shortcut for each of the contacts.
        // The same shortcut ID will be used when we show a bubble notification.
        return ShortcutInfoCompat.Builder(context, shortcutId)
                .setLocusId(LocusIdCompat.toLocusIdCompat(LocusId(shortcutId)))
                .setActivity(ComponentName(context, FragmentActivityMain::class.java))
                .setShortLabel(context.getString(R.string.app_name))
                .setLongLived(true)
                .setRank(1)
                .setIcon(IconCompat.createWithResource(context, R.drawable.silhouette))
                .setCategories(setOf("com.example.android.bubbles.category.TEXT_SHARE_TARGET"))
                .setIntent(
                        Intent(context, FragmentActivityMain::class.java)
                                .setAction(Intent.ACTION_VIEW)
                )
                .setPerson(
                        getPerson()
                )
                .build()
    }

    @WorkerThread
    fun showNotification(fromUser: Boolean) {
        val icon = IconCompat.createWithResource(context, R.drawable.silhouette)

        val pendingIntent = PendingIntent.getActivity(
                context,
                REQUEST_BUBBLE,
                // Launch BubbleActivity as the expanded bubble.
                Intent(context, FragmentActivityMain::class.java)
                        .setAction(Intent.ACTION_VIEW),
                PendingIntent.FLAG_UPDATE_CURRENT
        )

        val style = NotificationCompat.MessagingStyle(getPerson())
                .addMessage("test Message!", System.currentTimeMillis(), getPerson())
                .setGroupConversation(false)

        var builder = NotificationCompat.Builder(context, CHANNEL_NEW_MESSAGES)
        // A notification can be shown as a bubble by calling setBubbleMetadata()


        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
            builder = builder.setBubbleMetadata(
                    NotificationCompat.BubbleMetadata.Builder()
                            // The height of the expanded bubble.
                            .setIntent(pendingIntent)
                            .setIcon(icon)
                            .setDesiredHeight(600)
                            .apply {
                                if (fromUser) {
                                    setAutoExpandBubble(true)
                                    setSuppressNotification(true)
                                }
                            }
                            .build()
            )
        }
        // The user can turn off the bubble in system settings. In that case, this notification
        // is shown as a normal notification instead of a bubble. Make sure that this
        // notification works as a normal notification as well.
        builder = builder.setContentTitle(context.getString(R.string.app_name))
                .setSmallIcon(R.drawable.silhouette)
                .setCategory(Notification.CATEGORY_MESSAGE)
                .setShortcutInfo(updateShortcuts())
                .addPerson(getPerson())
                .setPriority(NotificationCompat.PRIORITY_HIGH)
                .setShowWhen(true)
                .setStyle(style)
                // The content Intent is used when the user clicks on the "Open Content" icon button on
                // the expanded bubble, as well as when the fall-back notification is clicked.
                .setContentIntent(
                        PendingIntent.getActivity(
                                context,
                                REQUEST_CONTENT,
                                Intent(context, FragmentActivityMain::class.java)
                                        .setAction(Intent.ACTION_VIEW),
                                PendingIntent.FLAG_UPDATE_CURRENT
                        )
                )


        setUpNotificationChannels()
        notificationManager.notify(888, builder.build())
    }

    fun dismissNotification(id: Long) {
        notificationManager.cancel(id.toInt())
    }
}

And I am calling it using

NotificationHelper notificationHelper = new NotificationHelper(context, String.valueOf(System.currentTimeMillis()));
        notificationHelper.showNotification(true);

Update Here is the manifest -

<activity
            android:name=".display.FragmentActivityMain"
            android:allowEmbedded="true"
            android:configChanges="keyboardHidden|orientation|screenLayout"
            android:launchMode="singleTask"
            android:resizeableActivity="true"
            android:windowSoftInputMode="stateHidden|adjustResize">
            <intent-filter>
                <action android:name="android.intent.action.SEND" />
                <category android:name="android.intent.category.DEFAULT" />
                <data android:mimeType="text/plain" />
            </intent-filter>
        </activity>