without customview its able to center actionbar title. its perfectly working for navigation drawer as well
int titleId = getResources().getIdentifier("action_bar_title", "id", "android");
TextView abTitle = (TextView) findViewById(titleId);
abTitle.setTextColor(getResources().getColor(R.color.white));
DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);
abTitle.setGravity(Gravity.CENTER);
abTitle.setWidth(metrics.widthPixels);
getActionBar().setTitle("I am center now");
Happy coding. thank you.