autopkgtest-build-qemu: don't use ext4 features unsupported in the target release

grub2 is currently unable to deal with ext4 features large_file and metadata_csum_seed. As a consequence, e2fsprogs have temporarily disabled these by default and vmdb2 likewise disables them for now. Both probably will change. In a similar vein, the version of e2fsprogs in jessie and trusty does not support metadata_csum. As such I propose that autopkgtest handles these cases with release-specific workarounds.

Link: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1844012