Berlin (dpa) — When Google introduced its first Pixel smartphone in October 2016, the company wanted to show that devices with the Android operating system could be serious challengers to the iPhone. Eight years on, it’s clear that building a phone wasn’t just a fad for the search engine giant. This can be seen in the many detailed improvements to the latest Pixel generation. We tested three models: the Pixel 9, the Pixel 9 Pro XL with a 6.7-inch screen, and the folding Pixel 9 Pro Fold. Pixel Fold: Slim and stable The Pro Fold is the most expensive of the three. It is slimmed down compared to…