Log Message:
security/libdecaf: Update to v1.0.2

Changes since v1.0.1:

July 13, 2022:
    Fix a security bug and an issue.

    Point::steg_encode was leaving the 24 high bits of the buffer as zero.
    It also ignored the size parameter.  The size parameter has now been
    removed, the zeros fixed and a test added to make sure that it is fixed.

    Per https://github.com/MystenLabs/ed25519-unsafe-libs, deprecate eddsa
    signing with separate pubkey and privkey input. Instead decaf_ed*_keypair_sign.

    Release v1.0.2.