Is it worth putting a job under common app activities if I only did it for one summer?
Yes (unless you’ve already filled all the activities slots with longer duration/more significant ECs).
But don’t colleges dislike EC’s with little commitment?
It’s not that they inherently dislike little commitment (versus none?), it’s just that depth is generally better than breadth. In general that applies to clubs - people who are a “member” of 15 clubs but have not contributed significantly to any vs people who are a member of 5 and hold leadership roles in them. An entire summer at a job probably adds up to more hours than a year’s worth of club activities anyways.
As a high school student working a job for just the summer is not unexpected. Students rarely work full time while going to high school. It’s a bit like an internship really. I would put it down.