Confirmed your fix Ben. Changed /usr/lib/python2.7/dist-packages/cloudinit/CloudConfig/cc_grub_dpkg.py, removed /var/lib/cloud/instance/sem/config-grub-dpkg, and ran cloud-init-cfg grub-dpkg. The cloud-init log confirmed xvda was selected and an upgrade of grub worked.
Confirmed your fix Ben. Changed /usr/lib/ python2. 7/dist- packages/ cloudinit/ CloudConfig/ cc_grub_ dpkg.py, removed /var/lib/ cloud/instance/ sem/config- grub-dpkg, and ran cloud-init-cfg grub-dpkg. The cloud-init log confirmed xvda was selected and an upgrade of grub worked.