Handle request permission

LaunchActivity.java

public class LaunchActivity extends AppCompatActivity {

  ...

  @Override
  public void onRequestPermissionsResult(int requestCode,
                                         @NonNull String permissions[],
                                         @NonNull int[] grantResults) {
    switch (requestCode) {
      case REQUEST_CODE_READ_SMS: {
        // Unconditionally start the phone number confirmation activity.
        startActivity(new Intent(this, PhoneNumerConfirmationActivity.class));
      }
    }
  }
}