Revert "Revert "releasetools: Allow using futility-host to sign old TF.zip."" am: 77620b5a45 am: 9eea2cde67 am: 8fa3351890 am: 80e1a413e9 am: 853fe20064 am: 1df9591d8f
am: d99eb68921

Change-Id: I71a9e680f2da90fc56eee0f562fe3c7900b55bc1