Summary:
Preflight checks for manually provisioned nodes now also check for the node's clock
to be synced, instead of just having a sync service running.

Also fixed small bug with clock sync script and ntpd

Test Plan:
ran preflight checks on a node with each time sync service, validating
it will check for clock skew

Reviewers: muthu, nsingh

Reviewed By: muthu, nsingh

Subscribers: yugaware

Differential Revision: https://phorge.dev.yugabyte.com/D41105