Exclude libclang_rt from checking vndk list

libclang_rt libs are prebuilt libs that have different names by the
architecture they are built.

Bug: 77931086
Bug: 77816590
Bug: 67002788
Test: 'm check-vndk-list' for various architectures.
Change-Id: Iacb3979b6e5df7e9ba8073470aab23c603b4db55