GB polyps less than 5 mm are almost always benign and caused by cholesterolosis.
A followup ultrasound is advised after a year to ensure not growing. Polyps 6-10 mm. need more close followup, 3 and 6 months, then yearly. Polyps 10 mm and larger may be cancerous, 20 mm and up almost always malignant. Yours is tiny, no worry, do US in a year. If you have pain, you should see your provider.