If you cannot manage to turn fontNameResId into a String earlier I would recommend

if (this.style.fontName != null || this.style.fontNameResId != 0) {
    String font = this.style.fontName != null ? this.style.fontName : resources.getString(this.style.fontNameResId;
    setTextWithCustomFont(text, font);
} else { ....

Things maybe a little more condensed but then you don't have two if statements trying to do the same thing.