Rinse the rice under cold water. In a pot, combine rinsed rice with water and a pinch of salt. Bring to a boil, reduce heat to low, cover, and simmer until tender (about 15 minutes). Remove from heat and let it sit covered.
Pat chicken dry and season with chili powder, salt, and pepper. Heat a skillet over medium-high heat and cook chicken until golden brown and cooked through (about 6-8 minutes). Tent with foil to rest.
In the same skillet, char thawed corn until blistered. Mix with sour cream, mayonnaise, lime juice, salt, and pepper.
Assemble bowls by layering rice, chicken, street corn mixture, diced avocado, cilantro, and cheese.