I want the message text within my dialog box to be center aligned.
Of course, you can always set the gravity of the original text view. This allows you to not have to worry about formatting and padding.
For example
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Title");
builder.setMessage("Message");
builder.setPositiveButton("OK", null);
AlertDialog dialog = builder.show();
// Must call show() prior to fetching text view
TextView messageView = (TextView)dialog.findViewById(android.R.id.message);
messageView.setGravity(Gravity.CENTER);