Allow merging product_services into /product

Allow devices to specify TARGET_COPY_OUT_PRODUCT_SERVICES := product,
which in effect treats all product_services modules the same as product
modules.

Do not generate license and build props for product_services when
this settings is enabled.

Bug: 113098451
Test: boot downstream product
Change-Id: Id51230b969900bebcf19d0138dfd6187dfce25b1