Bechira is defined by the ramchal as the ability to choose right and wrong. As yidden, we have more opportunities to decide these things, because everything we do is either a mitzvah or an aveirah; there’s no “neutral” action, as explained in chovos halevavos the same is not true for goyin; they only hhave67 kitzvos, and their service of Hashem is auxillary, it is not an all encompassing lifestyle where every machshava dibur and maaseh is sanctified to be in sync with the ratzon Hashem..
It’s fitting therefore that they have bechira, but only as fas as their decisions which impact the 7 mitzvos and their subcategories.