Refactor genrules to explicitly list inputs
Directories in srcs are not compatible with the migration to Bazel, we
are restricting their use in Soong.
Test: m libxml2_schema_fuzz_corpus libxml2_xml_fuzz_corpus
libxml2_xpath_fuzz_corpus
Change-Id: I3e9875370a3c4e4ac0c055eae93d9a9026483527