At this time, we do not intend to support the Cinnamon desktop due
to its reliance on X11 and the lack of interest by the upstream
Fedora Cinnamon SIG for ARM for their spin.
This mostly reverts commit a3c3a8137f.
According to the documentation, an empty file triggers firstboot
mode. Since we're not using a read-only root filesystem, we do not
need to leverage any other tricks here and we can just have no file
present.
KIWI currently configures grub2 slightly incorrectly,
such that installing new kernels does not correctly
switches the default kernel to the new one.
Work around this while we wait for a fix in KIWI
to deal with this problem.
Reference: https://github.com/OSInside/kiwi/issues/2198
