This repo does not support Python 2 anymore, so we don't need
six for compatibility between Python2 and 3, convert six usage to Python
3 code.
Change-Id: I3edab6e67ac79d14fe9d38f6f75abfd50030fa1e
Needed-By: https://review.opendev.org/701743
Add wrapper functions for binascii hexlify/unhexlify to deal with the
conversion between bytes and str.
Partial-Bug: #1755413
Change-Id: I8351b30b62ba19290e05c30499c3588649f8f367
Signed-off-by: Zhao Chao <zhaochao1984@gmail.com>