Comment 4 for bug 1950106

These are the notifications that I think we need (at least that I can find at the moment):

osinfo
- when changing the default os in config the general osinfo needs to be updated with the new default: https://github.com/canonical/maas-ui/issues/148#issuecomment-545908773

default_min_hwe_kernel
- when changing the default min HWE kernel in config the general default_min_hwe_kernel needs to be updated with the new default

hwe_kernels
osinfo
default_min_hwe_kernel
architectures
- after images are synced these values need to be updated: https://bugs.launchpad.net/maas/+bug/1964143