header-abi-dumper: Add omp.h workaround

This commit adds <omp.h> workaround for LL-NDK/VNDK/VNDK-SP libs that
use OpenMP.  This workaround is necessary because clang-3289846 does not
have omp.h and header-abi-dumper will stick to that version for a while.

Bug: 77161122
Test: Mark libneuralnetworks as LLNDK and rebuild it.
Change-Id: I8f3fb7aea7922dd7431b882e310991a91a2f5d43
Merged-In: I8f3fb7aea7922dd7431b882e310991a91a2f5d43
(cherry picked from commit cf432585)