Cook rice according to package directions. Meanwhile, in a resealable jar, whisk vinegar and sugar until dissolved; add red onion. Seal and refrigerate 30 minutes or up to 2 weeks. In a small bowl, stir together mayonnaise and chili sauce; refrigerate, covered, until serving., In a large skillet or wok, toss chicken, soy sauce, sesame oil and honey. Cook and stir over medium-low heat until chicken is heated through, 5-7 minutes. To serve, divide rice among 4 serving bowls. Top with chicken mixture, avocado, cucumber, sprouts, pickled onions, spicy mayonnaise and, if desired, green onions and sesame seeds.