Slow-Cooker Chicken Gumbo

1 pound boneless skinless chicken breasts, cut into 2-inch pieces

One 10-ounce package frozen okra, thawed

2 links andouille sausage, diced

1 cup chopped onions

2 celery stalks, chopped

1 green bell pepper, seeded and chopped

1 teaspoon dried thyme

1 teaspoon dried oregano

1/2 teaspoon salt

2 bay leaves

1/2 teaspoon onion powder

1/2 teaspoon garlic powder

1/2 teaspoon mustard powder

1/4 teaspoon cayenne pepper

1/4 teaspoon ground black pepper

2 cups reduced-sodium chicken broth

2 cups reduced-sodium tomato juice

2 cups cooked rice