Spray 3 1/2- to 4-quart slow cooker with cooking spray. In cooker, mix all ingredients except mixed vegetables, rice and salt.
Cover; cook on Low heat setting 6 to 8 hours.
Break chicken into bite-size pieces by pulling apart with 2 forks. Stir in mixed vegetables and rice. Increase heat setting to High. Cover; cook 20 minutes longer or until rice is tender. Season with 1/2 teaspoon salt.