That just the way kids talk with their urban street slang
I don't care that you heard it from a movie where the main characters are AFrican American. This apparently what some youth say to each other. And that is where that came from?
These are young teenaged Autobots
My teenaged cousins who are in their late teens and early 20s speak in slang and in internet lingo all the time. This is no different from saying words like "PWN3D" or "Noob" or "have your ass handed back to you". Its all just urban slang.
Asian and white kids say pop a cap in yo ass just as much as black kids do so what is your point??