[HTML5-CEF] raspberrypi4 and qemux86_64 images broken due to missing xz dependency

Hi @Edi Feschiyan, according to the logs it fails because it can't find the xz executable. I tried to reproduce the issues removing xz locally, but the issue could not be reproduced. Would you please cherry-pick the tentative fix (https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl-demo/+/29184) and check if it works in your environment?