Remove workaround for libclang_rt.ubsan* vndk libs

libclang_rt.ubsan* VNDK core libraries are no longer built
for all arch flavors. Now, only the TARGET[_2ND]_ARCH-specific
libs are builts. Therefore no need to filter-out and re-add
libclang_rt.ubsan* VNDK core libraries.

Test: m -j vndk
Change-Id: I48080c1cd546cfc9f14313a3c9559d5c1bb2fdbe