Pass extra args from multiproduct_kati to config.

Allows specifying make goals when using multiproduct_kati, for example:
$ multiproduct_kati -only-config dump-products

This makes dumping products with multiproduct_kati easier than before.

Test: multiproduct_kati -only-config -products=full,aosp_arm64 -out=/tmp/p dump-products
Change-Id: If526bd2ba1b7bbadcb230c020202ef9e421e1852