Add two more vendor-specific properties

target.vendor.exclude_static_libs: this is the static counterpart of
target.vendor.exclude_shared_libs. This removes the libs from the static
dependency when build the vendor variant.

target.vendor.version_script: vendor-specific version script.

Right now, these are required to merge libseliux_vendor into libselinux
and make it vendor_avaialble:true. libselinux is using libpackageparser
which is a platform-only library. The vendor variant of libselinux can't
depend on the library.

Bug: 66914194
Test: lunch aosp_arm64_ab-userdebug; m libselinux.vendor

Change-Id: I163e634f2f54d419f9471a585a3b04731b63f809