ApiLint: Allow parsing 2.0 API signature files

Test: tools/apilint/apilint_sha.sh HEAD
Test: python tools/apilint/apilint_test.py
Change-Id: Id2e1792392b3626746f1ec99f481d0cb27e523a1
(cherry picked from commit d170961b02bf67189ddd14f358c9f263009df786)
2 files changed