애뮬레이터 앱종료시 초기화문제

Question

package com.example.myapplication;
import android.content.Intent;
import android.content.SharedPreferences;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.AppCompatButton;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import java.io.InputStream;


public class MainActivity extends AppCompatActivity {
    private static final int REQUEST_CODE = 0;
    private ImageView imageView;
    EditText et_name, et_age;
    AppCompatButton bt_save;
    SharedPreferences sp;
    Gson gson;
    String contact_person;
    
    
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        imageView = findViewById(R.id.image);

        imageView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent();
                intent.setType("image/*");
                intent.setAction(Intent.ACTION_GET_CONTENT);
                startActivityForResult(intent, REQUEST_CODE);
            }
        });
        et_name = findViewById(R.id.et_name);
        et_age = findViewById(R.id.et_age);
        bt_save = findViewById(R.id.bt_save);
        imageView = findViewById(R.id.image);
        sp = getSharedPreferences("shared", MODE_PRIVATE);
        gson = new GsonBuilder().create();
        contact_person = sp.getString("contact_person", "");
        if (!contact_person.equals("")) {
            Person person = gson.fromJson(contact_person, Person.class);
            et_name.setText(person.getName());
            et_age.setText(person.getAge() + "");

        }

        bt_save.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                contact_person = "";
                String name = et_name.getText().toString();
                int age = Integer.parseInt(et_age.getText().toString());
                Person person = new Person(name, age);

                contact_person = gson.toJson(person, Person.class);

                SharedPreferences.Editor editor = sp.edit();
                editor.putString("contact_person", contact_person);

                editor.commit();

                Toast.makeText(MainActivity.this, "저장되었습니다", Toast.LENGTH_SHORT).show();
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == REQUEST_CODE) {
            if (resultCode == RESULT_OK) {
                try {
                    InputStream in = getContentResolver().openInputStream(data.getData());

                    Bitmap img = BitmapFactory.decodeStream(in);
                    in.close();

                    imageView.setImageBitmap(img);
                } catch (Exception e) {

                }
            } else if (resultCode == RESULT_CANCELED) {
                Toast.makeText(this, "사진 선택 취소", Toast.LENGTH_LONG).show();
            }

            SharedPreferences test = getSharedPreferences("test", MODE_PRIVATE);
            test.edit();

        }



    }
}

버튼을 클릭해서 갤러리에서 불러온 사진값이 에뮬레이터에서 앱을 종료하고 다시실행시 초기화 됩니다. 앱 재실행시 값을 유지하고싶은데 코딩을 어떻게 해야할까요?