(a) Nothing in the club and drinking establishment act shall be construed to prohibit a person from possessing, on premises licensed pursuant to such act, alcoholic liquor or cereal malt beverage not purchased from the licensee.

(b) Nothing in this section shall prevent a licensee from adopting a policy prohibiting the possession, on the licensee’s licensed premises, of alcoholic liquor or cereal malt beverage not purchased from the licensee.