cros-disks: bring back avfs based zip support

avfs based zip unpack support is used when user enables
--disable-new-zip-unpacker flag.

BUG=chromium:777254
TEST=enable --disable-new-zip-unpacker flag and confirm that zip can be
     unpacked.

Change-Id: I19b89b337dcd1687d8131008c7ac11963f84576d
Reviewed-on: https://chromium-review.googlesource.com/732797
Commit-Ready: Ben Chan <benchan@chromium.org>
Commit-Ready: Yuki Awano <yawano@chromium.org>
Tested-by: Ben Chan <benchan@chromium.org>
Reviewed-by: Ben Chan <benchan@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed