framework: Fix translation of hex values in AVCs
Audit encloses plain text values of path, name or exe fields in double
quotes to distinguish them from hex encoded values. Use this instead of
trying to hex-translate all values. The translation is done immediately
after parsing the AVC, hence all other attempts to hex translate could
be removed.
Use bytearray.fromhex(path).decode('utf-8') in python 3
(str.decode('hex') is invalid).
Keep using str.decode('hex') on python 2 to avoid issues with unicode
strings (which are not accepted by libselinux functions).
Fixes:
https://bugzilla.redhat.com/show_bug.cgi?id=1477236
Signed-off-by: Vit Mojzis <vmojzis@redhat.com>