libsepol: cil: Keep type[attribute] declarations when attributizing.

cil_android_attributize() uses a source policy to identify types and
attributes to be versioned according to the given version number, and
then proceeds to modify the provided target policy to provide this
versioning.  Previously, the versioned policy relied on a base policy
for the declarations of these type[attribute]s, but with multiple_decl
support added, the declarations can be made in both places.  This will
make the policy more robust and allow for greater flexibility and the
types of base policy used.

Bug: 37915794
Test: Builds 'n' boots.  non_plat_sepolicy.cil now contains the public
type[attribute] declarations.

Change-Id: Iaa084211a9e2774a7ed391888fb21c4c0cf955db
2 files changed