tests: fix i18n.sh regression test on arm64
The following errors are happening on the regression tests of i18n.sh on arm64 hirsute/impish:
Error: open failed. Test 'i18n (194) OPEN (octal) "/tmp/sdtest.3654-6536-J2ZwFM/file__post" RW' was expected to 'pass'. Reason for failure 'FAIL: open /tmp/sdtest.3654-6536-J2ZwFM/file__post failed - Permission denied'
...
The cause is a bash bug handling UTF-8 on subshells.
Fixes: https://bugs.launchpad.net/apparmor/+bug/1932331
Signed-off-by: Georgia Garcia georgia.garcia@canonical.com