Ansible launcher: retry publisher sync tasks

We sometimes see errors rsyncing data from the node or to the
log server.  Since these are all rsync commands, they are safe
to retry.  Attempt all post playbook rsyncs up to 3 times with
a 30 second delay between each attempt.

Change-Id: I329e1f1f31d53d82799e3485a912b76e2249d03f
1 file changed