Revert "Set boot.loader.grub.configurationLimit to 1 for gce/azure/amazon...

Revert "Set boot.loader.grub.configurationLimit to 1 for gce/azure/amazon images. Setting to 0 results in empty grub config."

The issue was that grub was not building the default entry which would
leave systems unbootable. This can now be safely reverted as the default
entry is being built once again.

This reverts commit fd1fb040.