Set certain sysctl(s) to configure system behavior appropriately

PR: https://github.com/truenas/middleware/pull/8130

This PR adds changes to set certain sysctl(s) which should always be set to configure system behavior appropriately. The `kernel.panic` and `kernel.panic_on_oops` sysctl(s) have been requested by mav to be configured always when the system boots as otherwise we don't see a clean reboot of the system on panic and instead it hangs indefinitely.