Set slow cooker to high. Cut pork into 4-in. pieces. Combine salt with chili powder, chili flakes and cumin. Rub into meat until fully coated. Season with pepper. Arrange pork in 1 layer in slow cooker insert. Add cinnamon stick, bay leaf, onion and garlic. Cover with lid and cook for 4 hours. Remove pork to a cutting board and let cool slightly. Using a fork, pull the pork apart into bite-sized pieces. Spoon 2 tbsp of drippings and cooked onions from slow cooker into a large non-stick frying pan set over medium-high. Add half of pork to hot pan and cook until edges are slightly crispy, 4 to 6 min. Repeat with remaining pork, adding additional drippings if needed. Serve immediately with Green-herbs rice and Mexican crema. Garnish with avocado wedges.