Add sdk version workaround for libclang_rt

libclang_rt.*.so depends on libc++, which is not a part of NDK.  Thus,
this workaround must be added in order not to break the build when the
prebuilt dependencies are checked.

Bug: 121358700
Test: make checkbuild
Change-Id: Icaeb7adf96fb72829053e198b659ebcb19a035fc