Add liveliness probe for openshift sync pod

Issue

• Sync pod failed to update node.openshift.io/md5sum or stop updating. Many times multiple nodes label were wrong while sync pods still running on those nodes. Restart sync pod solve the problem.
• It will be helpful to add liveliness probe to sync pod as it a very critical part of the platform. If any node in cluster doesn't have a valid md5sum, scale up playbook fails.
• what liveliness probe should do is check if md5sum of node-config.yml is equal to node's node.openshift.io/md5sum.