devicestate: ensure permissions of /var/lib/snapd/void are correct
* devicestate: ensure permissions of /var/lib/snapd/void are correct
During the testflinger testing I saw some failures in the
`tests/main/cwd` test where the permissions of the
`/var/lib/snapd/void` directory are incorrect. On systems that
use packaging tools we force the permissions to be 0111 on each
refresh (see `debian/snapd.postinst`). However no such mechanism
exists on core devices. So if for some reason the permissions get
corrupted they never get fixed.
This commit adds code that ensures the permissions are fixed
automatically here too.