RecyclerView error with images Android Studio

I load images in a recycler view but spaces appear in the bank:

Adapter:

   package com.example.recyclerview;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import java.util.ArrayList;

public class AdapterDatos extends RecyclerView.Adapter<AdapterDatos.ViewHolderDatos> {


    ArrayList<String> listDatos;

    public AdapterDatos(ArrayList<String> listDatos)
    {

        this.listDatos = listDatos;
    }



    @NonNull
    @Override
    public ViewHolderDatos onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view= LayoutInflater.from(parent.getContext()).inflate(R.layout.item_list,null,false);

        return new ViewHolderDatos(view);
    }

    @Override
    public void onBindViewHolder(@NonNull ViewHolderDatos holder, int position) {
       holder.asignarDatos(listDatos.get(position));
    }

    @Override
    public int getItemCount() {
        return listDatos.size();
    }

    public class ViewHolderDatos extends RecyclerView.ViewHolder {


        ImageView imagen;




        public ViewHolderDatos(@NonNull View itemView) {
            super(itemView);
            imagen=(ImageView)itemView.findViewById(R.id.imagen_dato);
        }

        public void asignarDatos(String s) {

            imagen.setImageResource(R.drawable.gato);

        }
    }
}

Main:

    package com.example.recyclerview;

import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.os.Bundle;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    ArrayList<String> listDatos;
    RecyclerView recycler;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        recycler=(RecyclerView)findViewById(R.id.RecyclerId);
        recycler.setLayoutManager(new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false));
        listDatos= new ArrayList<String>();

        for (int i=0;i<3;i++)
        {
            listDatos.add("Dato: " + i);
        }
       AdapterDatos adapter=new AdapterDatos(listDatos);
        recycler.setAdapter(adapter);

    }
}

XMLItems:

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    xmlns:android="http://schemas.android.com/apk/res/android">

    <ImageView
        android:id="@+id/imagen_dato"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</LinearLayout>