Change in NTP sync control on VM based HAOS images

[tadawson]

Describe the feature

The feature desired is a better tool to both reset the (s)NTP "timesyncd" target, as well as the means to disable it completely.

Use cases

Just about any VM based deployment that inherently has a better time source than the internet by default, or can be better served by syncing the underlying server.

Current workarounds

Changing the external source can be done via HAOS login via an editor, but the config is inexplicably read-only on the vol, prohibiting the simple task of "systemctl disable from trivially accomplishing this task.

Thus, there is no workaround to be able to rely on the host clock passed to the VM without timesyncd trying to fight it.

Anything else?

When running in a VM, clock is almost 100% provided by the underlying host of the VM, thus rendering any NTP on the VM uneeded at best, and conflicting at worst. If actually needed, the ability to choose a better source than an Internet based time source would also be great. For instance, I have my VM sitting on my primary which runs Stratum-0, but the default HA VM image looks outside for (at best) a T2 time source which is many orders of magnitude worse.