Nowhere in Africa is a German film that takes place during World War 2, but in Kenya, not a place one associates with that conflict.
Cowboys and Aliens - about the little known alien invasion of the American West in the 19th century.
One film, Safari, which might qualify was just on today. I didn’t watch it so can’t tell you how much of it was actually about the Mau Mau Uprising.
Safari
Simba
Something of Value
And those weren’t all foreign films with no-name actors, either - Rock Hudson, Sydney Poitier, Dirk Bogarde, Victor Mature and Janet Leigh…
The Milagro Beanfield War - not really a war but hey, directed by Robert Redford with Christopher Walken, Melanie Griffith & Ruben Blades how bad can it be? I liked it, IIRC.
The Panama Deception (more of a documentary than a war film, I suppose), about the Noriega skirmish.