要确保Android通知显示为Heads Up，你可以使用以下代码示例：

1. 设置通知渠道

private void createNotificationChannel() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        CharSequence name = "Channel Name";
        String description = "Channel Description";
        int importance = NotificationManager.IMPORTANCE_HIGH;
        NotificationChannel channel = new NotificationChannel("channelId", name, importance);
        channel.setDescription(description);
        channel.setShowBadge(true);
        channel.setLockscreenVisibility(Notification.VISIBILITY_PUBLIC);

        NotificationManager notificationManager = getSystemService(NotificationManager.class);
        notificationManager.createNotificationChannel(channel);
    }
}

在创建通知之前，调用此方法来创建通知渠道。将"channelId"替换为你自己的通知渠道ID，以及设置其他适当的通知渠道属性。

2. 创建Heads Up通知

private void showHeadsUpNotification() {
    Intent intent = new Intent(this, MainActivity.class);
    PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);

    NotificationCompat.Builder builder = new NotificationCompat.Builder(this, "channelId")
            .setContentTitle("Heads Up Notification")
            .setContentText("This is a heads up notification.")
            .setPriority(NotificationCompat.PRIORITY_HIGH)
            .setDefaults(Notification.DEFAULT_ALL)
            .setAutoCancel(true)
            .setContentIntent(pendingIntent)
            .setFullScreenIntent(pendingIntent, true)
            .setSmallIcon(R.drawable.ic_notification);

    NotificationManagerCompat notificationManager = NotificationManagerCompat.from(this);
    notificationManager.notify(0, builder.build());
}

调用此方法来显示Heads Up通知。确保将"channelId"替换为你之前创建的通知渠道ID，并根据需要设置其他通知属性。

这些代码示例将确保你的Android通知以Heads Up的形式显示。