How do I change the icon of the navigation drawer from the hamburger icon to something else?

Question

I've tried doing this but it doesn't work, because I'm still seeing the original hamburger icon:

Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        getSupportActionBar().setDisplayShowTitleEnabled(false);
drawer = findViewById(R.id.drawer_layout);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
                this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.addDrawerListener(toggle);
        toggle.syncState();

        getSupportActionBar().setHomeButtonEnabled(true);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        getSupportActionBar().setHomeAsUpIndicator(R.drawable.menu_icon);
        toggle.setHomeAsUpIndicator(R.drawable.menu_icon);

What can I do to fix this? Another thing is that I'm using this @style/ToolbarColoredBackArrow so is that obstructing the icon from showing up?