Как я выполняю итерации набора.Net IList в обратном порядке?

Попробуйте следующее:

//Find the action bar for customizations
    final ActionBar ab = getSupportActionBar();
    assert ab != null;

    //Make the action bar display an up arrow and set its drawable and color
    ab.setDisplayHomeAsUpEnabled(true);
    final Drawable upArrow = ResourcesCompat.getDrawable(
            getResources(),
            R.drawable.abc_ic_ab_back_mtrl_am_alpha, //this is the <- arrow from android resources. Change this to the thing you want.
            null);
    assert upArrow != null;
    upArrow.setColorFilter(
            ContextCompat.getColor(
                    getApplicationContext(),
                    R.color.white // change this to the color you want (or remove the setColorFilter call)
            ),
            PorterDuff.Mode.SRC_ATOP);
    ab.setHomeAsUpIndicator(upArrow);