/lib/systemd/system/grub-initrd-fallback.service may be sequenced too early

I'm currently working on this. It's unclear, after brief testing on AWS, what the impact of grub-initrd-fallback.service is (even when re-ordering it's start); but the changes are done and I'll include them with the grub2 merge.

This bug was fixed in the package grub2 - 2.04-1ubuntu1

---------------
grub2 (2.04-1ubuntu1) eoan; urgency=medium

  * Merge against Debian; remaining changes:
    - debian/control: Update Vcs fields for code location on Ubuntu.
    - debian/control: Breaks shim (<< 13).
    - debian/patches/linuxefi.patch: Secure Boot support: use newer patchset
      from rhboot repo, flattened to a single patch.
    - debian/patches/install_signed.patch, grub-install-extra-removable.patch:
      - Make sure if we install shim; it should also be exported as the default
        bootloader to install later to a removable path, if we do.
      - Rework grub-install-extra-removable.patch to reverse its logic: in the
        default case, install the bootloader to /EFI/BOOT, unless we're trying
        to install on a removable device, or explicitly telling grub *not* to
        do it.
      - Install a BOOT.CSV for fallback to use.
      - Make sure postinst and templates know about the replacement of
        --force-extra-removable with --no-extra-removable.
    - debian/patches/ubuntu-support-initrd-less-boot.patch: allow non-initrd
      boot config.
    - debian/patches/ubuntu-add-initrd-less-boot-fallback.patch: If a kernel
      fails to boot without initrd, we will fallback to trying to boot the
      kernel with an initrd.
    - debian/patches/ubuntu-mkconfig-leave-breadcrumbs.patch: make sure
      grub-mkconfig leaves a trace of what files were sourced to help generate
      the config we're building.
    - debian/patches/ubuntu-efi-console-set-text-mode-as-needed.patch: in EFI
      console, only set text-mode when we're actually going to need it.
    - debian/patches/ubuntu-zfs-enhance-support.patch: Better ZFS grub support.
    - Disable os-prober for ppc64el on the PowerNV platform, to reduce the
      number of entries/clutter from other OSes in Petitboot
    - debian/patches/ubuntu-shorter-version-info.patch: Only show the upstream
      version in menu and console, and hide the package one in a
      package_version variable.
    - Verify that the current and newer kernels are signed when grub is
      updated, to make sure people do not accidentally shutdown without a
      signed kernel.
    - debian/default/grub: replace GRUB_HIDDEN_* variables with the less
      confusing GRUB_TIMEOUT_STYLE=hidden.
    - debian/rules: shuffle files around for now to keep build artefacts
      for signing at the same location as they were expected by Launchpad.
    - debian/rules, debian/control: enable dh-systemd.
    - debian/grub-common.install.in: install the systemd unit that's part of
      initrd fallback handling, missed when the feature landed.
    - debian/build-efi-images: add http module to NET_MODULES.
  * debian/patches/linuxefi*.patch: Flatten linuxefi patches into one.
  * debian/patches: rename patches to use "-" as a separator rather than "_".
  * debian/patches: rename Ubuntu-specific patches and commits to add "ubuntu"
    so it's clearer which are new or changed when doing a merge.
  * debian/patches/ubuntu-fix-lzma-decompressor-objcopy.patch: fix FTBFS due
    to objcopy building an invalid binary padded with zeroes (LP: #1833234)
  ...