Open this photo in gallery: Samsung Electronics’ new Galaxy Z Flip 5 and Z Fold 5 foldable smartphones, in Seoul, South Korea, on July 26.KIM HONG-JI/Reuters Samsung Electronics unveiled its latest foldable smartphones on Wednesday, keeping prices around the same level three years in a row as it seeks to challenge Apple’s AAPL-Q dominance in the premium market. The world’s largest smartphone maker pioneered the segment in 2019, betting that it would appeal to consumers looking for a bigger screen to consume content, while its foldable displays keep the overall phone size compact. Foldable phones remain a niche product category,...