I think black people in Germany are usually relatively recent immigrants directly from Africa and so they don't have much culture in common with African Americans. Attitudes among African Americans vary, and a lot of that variation is related to social class. Pretty much no one wants to hear white people saying it but working-class African Americans living in segregated neighborhoods are much more likely to say it themselves than middle-class, more assimilated African Americans are. However, the attitudes of the (frequently white) people who might get you in trouble for being racist are much more uniform; the "common standard" is about what these people think.