Since a lib in exclude_shared_libs are not used for the vendor variant,
it should also be removed from the export_shared_lib_headers.
Bug: 62471389
Test: BOARD_VNDK_VERSION=current m -j libxml2.vendor successful
(libxml2 has libicuuc in both exported_shared_lib_headers and
exclude_shared_libs for the vendor variant)
Merged-In: Ic9ddbd7be3c76df563e428ba2409a03bd2e1e113
Change-Id: Ic9ddbd7be3c76df563e428ba2409a03bd2e1e113