Warm the vegetable oil in a nonstick skillet set over medium-high heat. Introduce the ground pork and cook thoroughly, breaking it apart until no pink remains, for approximately 5 minutes. Drain any rendered fat. Incorporate the minced garlic and ginger, sautéing briefly until aromatic, about 20 seconds. Fold in the onion, carrot, cabbage, water chestnuts, and scallions. Sauté for an additional 2 to 3 minutes until the vegetables soften. Season with salt, black pepper, garlic powder, soy sauce, and sesame oil. Remove from heat and allow the filling to cool until manageable. Lay a lumpia wrapper on a clean surface in a diamond orientation. Place roughly 2 1/2 tablespoons of filling near the bottom point, leaving 1 1/2 inches of space. Shape the filling into a 4 to 5 inch strip. Fold the bottom corner over the filling, then tuck in the sides to form an envelope. Roll tightly toward the top point, moistening the final 2 inches with water to seal. Position seam side down on a plate and cover with plastic wrap. Repeat until all filling and wrappers are used. To cook, heat about 1 inch of vegetable oil in a heavy skillet over medium heat until the oil reaches 350°F. Fry 4 lumpia at a time, seam side down, without crowding, for 1 to 2 minutes per side until golden and crisp. Transfer to a plate lined with paper towels to drain excess oil. Serve at once accompanied by sweet chili sauce.