Chicken Parm Casserole

1 tablespoon olive oil
4 cups cooked chicken, diced
1 ½ cup marinara sauce
2 cups cauliflower rice
1+ cup mozzarella cheese, shredded
½ cup shredded parmesan cheese
4 oz cream cheese
1 teaspoon garlic salt
½ teaspoon ground black pepper
½ teaspoon Italian seasoning