title: getDiskStats failed with result NOT_SUPPORTED and size 0
body: <p>please help me with this problem
  my app crash when I try to run this code
  I have attached a screenshot of my logcat
  I have implemented source code from this link for the country code spinner
  <a href="https://github.com/joielechong/CountryCodePicker" rel="nofollow noreferrer">https://github.com/joielechong/CountryCodePicker</a>
  I am trying to make an activity to get user phone number and save the data entered by user to firebase Firestore</p>
  
  <p><a href="https://i.stack.imgur.com/2dqwt.png" rel="nofollow noreferrer">logcat screenshot</a></p>
  
  <p>my activity java code on android studio</p>
  
  <pre><code>import android.content.Context;
  import android.content.Intent;
  import android.support.annotation.NonNull;
  import android.support.v4.view.ViewPager;
  import android.support.v7.app.AppCompatActivity;
  import android.os.Bundle;
  import android.util.Log;
  import android.view.KeyEvent;
  import android.view.View;
  import android.widget.EditText;
  import android.widget.Toast;
  
  import com.google.android.gms.tasks.OnFailureListener;
  import com.google.android.gms.tasks.OnSuccessListener;
  import com.google.firebase.auth.FirebaseAuth;
  import com.google.firebase.auth.FirebaseUser;
  import com.google.firebase.firestore.FirebaseFirestore;
  import com.rilixtech.CountryCodePicker;
  
  import java.io.FileNotFoundException;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.util.HashMap;
  import java.util.Map;
  
  public class introPage extends AppCompatActivity {
      FirebaseAuth mAuth;
      CountryCodePicker ccp;
      EditText phoneNumber;
      String countryName;
      String phoneNum;
      int countryCode;
      FirebaseFirestore db;
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      ccp = (CountryCodePicker) findViewById(R.id.ccp);
      phoneNumber = (EditText)findViewById(R.id.phoneNumberEditText);
      phoneNum="";
      countryCode = 0;
      countryName="";
      setContentView(R.layout.activity_intro_page);
  
  
  
  
      if(mAuth == null) {
          mAuth = FirebaseAuth.getInstance();
      }
  
      if(db == null) {
          db = FirebaseFirestore.getInstance();
      }
      ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);
      viewPager.setAdapter(new CustomPagerAdapter(this));
  }
  
  @Override
  public void onBackPressed() {
      //super.onBackPressed();
      Toast.makeText(getApplicationContext(),"long press to sign out",Toast.LENGTH_SHORT).show();
  
  
  }
  
  @Override
  public boolean onKeyLongPress(int keyCode, KeyEvent event) {
      if (keyCode == KeyEvent.KEYCODE_BACK)
      {
          mAuth.signOut();
          startActivity(new Intent(introPage.this, LoginActivity.class));
          finish();
  
          return true;
      }
      return super.onKeyLongPress(keyCode, event);
  }
  
  
  
  public void getPhoneDetails(View view){
  
      if(phoneNumber.getText().toString().length()==0){
  
          Toast.makeText(getApplicationContext(),"Please key in phone number", Toast.LENGTH_SHORT).show();
  
  
      }else{
  
  
          FirebaseUser currentUser = mAuth.getCurrentUser();
          String id = "";
          id = currentUser.getUid().toString();
  
          countryName = ccp.getSelectedCountryName();
          countryCode = ccp.getSelectedCountryCodeAsInt();
          phoneNum = phoneNumber.getText().toString();
  
          Map&lt;String, Object&gt; infoUpdate = new HashMap&lt;&gt;();
          infoUpdate.put("country", countryName);
          infoUpdate.put("countryCode", countryCode);
          infoUpdate.put("phoneNumber", phoneNum);
  
          db.collection("users").document(id).update(infoUpdate)
                  .addOnSuccessListener(new OnSuccessListener&lt;Void&gt;() {
                      @Override
                      public void onSuccess(Void aVoid) {
                          Toast.makeText(getApplicationContext(), "Phone added", Toast.LENGTH_SHORT).show();
                          String storeData = "done intro";
                          try {
                              FileOutputStream fOut = openFileOutput("doneIntro",Context.MODE_PRIVATE);
                              fOut.write(storeData.getBytes());
                              fOut.close();
                          } catch (FileNotFoundException e) {
                              e.printStackTrace();
                          } catch (IOException e) {
                              e.printStackTrace();
                          }
                          startActivity(new Intent(introPage.this,barcodePage.class));
  
  
                      }
                  })
                  .addOnFailureListener(new OnFailureListener() {
                      @Override
                      public void onFailure(@NonNull Exception e) {
                          Toast.makeText(getApplicationContext(), "ERROR" + e.toString(), Toast.LENGTH_SHORT).show();
                          Log.d("TAG", e.toString());
                      }
                  });
  
  
  
      }
  
  
  }
  
  
  
  
  
  }
  </code></pre>