Custom Serialization in Java SDK 1.10 for MongoDB

Hello,

I'm currently working with Java SDK 1.10 to store a POJO in MongoDB, and I've encountered an issue with the default serialization. When I save the POJO, the result is stored as a string in MongoDB, like this:

`value: '{product: "prod", name: "example"}'`

I attempted to create a custom serialization using a Jackson object mapper, but unfortunately, the result remains the same:

`OBJECT_MAPPER.writeAsByte(pojo)`

What I'm aiming for is to have the POJO stored as an object in MongoDB, like this:

```
value: {
product: "prod",
name: "example"
}
```