mUnLocked = listItem.findViewById(R.id.unlock);
 mUnLocked.setOnClickListener(new View.OnClickListener() {
    @Override
      public void onClick(View view) {
            ImageView icon = (ImageView) view;
            icon.setImageResource(R.drawable.ic_lock_outline_black_24dp);
            icon.setVisibility(View.VISIBLE);
        }
    });