Summary:
health checks will now look for the running ntp service, rather
then the first install service. This allows customers to install
ntpd without removing chrony, and have the health check still
function correctly.

Test Plan:
validated health checks still pass
installed ntp and chrony, with ntp running. Health checks passed

Reviewers: anijhawan, amalyshev

Reviewed By: anijhawan, amalyshev

Differential Revision: https://phorge.dev.yugabyte.com/D42181