For some internal branches, vendor.img isn't built, so there
is no need to build super image / super split images there.
Test: remove vendor.img and VENDOR/ from target_files_intermediates, then
run add_img_to_target_files
Fixes: 120634805
Change-Id: I2834a27ce232538f203733c204dd257279c789fc
For non-retrofit (launch) devices, super.img is used for factory, so
source images should be from target_files.
In this change, build-superimage-target procedure is converted to a
more flexible script so that it can be built.
Bug: 119322123
Test: build target files for device launch with dynamic partitions
Change-Id: I6ee0cc3e145357dfc74be248f81f5f8f4e51fc5c
