Unbreak user builds

This unbreaks user builds broken by recently landed changes to secilc
which is now aggressively removing attributes which aren't used in
allow rules, even when they are used in other places, such as being
referenced from *_contexts files.

User builds are broken by vndservice_manager_type not being found when
checkfc is run for *vndservice_contexts targets.

Test: On a clean user build: mmma system/sepolicy
Bug: 37319524
Bug: 36508258
Change-Id: I4a1727a74122ecd9020c3831462d56a65ee6d304