Commit d08605f4 ("kleaf: Add support for specifying modules for
recovery/charger") accidentally made it so that kleaf always tries
to generate the vendor[_kernel]_boot.modules.* lists, even when
neither vendor_boot.img or vendor_kernel_boot.img need to be built.

Fix this by only attempting to generate those artifacts if either
vendor_boot.img or vendor_kernel_boot.img need to be built.

Bug: 324304750
Fixes: d08605f4 ("kleaf: Add support for specifying modules for recovery/charger")
Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com>
(cherry picked from https://android-review.googlesource.com/q/commit:100076d823899780662a6fdec71f92be35f6d9f7)
Merged-In: I31ec16fc543e55f33319e017c7d5976e825f581d
Change-Id: I31ec16fc543e55f33319e017c7d5976e825f581d