docs: Fixing Issue with code for Adding Tabs topic

    private TabContentFragment mFragment;

    // Called to create an instance of the listener when adding a new tab

    public TabListener(TabContentFragment fragment) {

    public MyTabListener(TabContentFragment fragment) {

        mFragment = fragment;

    }

    @Override

    public void onTabSelected(Tab tab, FragmentTransaction ft) {

        ft.add(R.id.fragment_content, mFragment, null);

    }

    @Override

    public void onTabUnselected(Tab tab, FragmentTransaction ft) {

        ft.remove(mFragment);

    }

    @Override

    public void onTabReselected(Tab tab, FragmentTransaction ft) {

        // do nothing

    }