Revert "Revert "releasetools: Allow using futility-host to sign old TF.zip."" am: 77620b5a45 am: 9eea2cde67 am: 8fa3351890 am: 80e1a413e9 am: 853fe20064
am: 1df9591d8f

Change-Id: I9090f06c8ea27efd479414b924e763d0726ab3cd