Hello Michi,
are you talking about AG AS7 cartridge [1]? I'm afraid this is not possible without manually editing content from provisioned cartridge (see instructions from Matthias), looking into original AS7 cartridge, the hook responsible for loading custom configuration was removed [2] [3].
I have NOT filled a feature request to make it possible as this feature is available for WildFly one (you just need to put file there and enable via ENV variable) [4] as AS7 cartridge have been officially deprecated.
Cheers,
Karel