Add support for TLS_FALLBACK_SCSV

Includes changes to openssl.config not present in the original
commit.

Bug: 17750026
(cherry-picked from commit 9a68a8fb86e7440763286e3ea8578099abd598e7)

Change-Id: I89ed89b87b4f4eeeddb6de0c6ad1d48cb6d0ee7b