Remove low-value logging from publication codepath

Previously, the pipeline publish codepath emitted log messages
with almost no diagnostic value other than a "comfort bump".
However the sheer volume of these message was overwhelming
logstash in the CI gate.

We remove the worst offenders from that codepath.

Change-Id: If630593e8f755ccc1ede16941459daac30d284ff
Closes-Bug: #1328596
(cherry picked from commit 5f8a1fbf804c9572b777eb6af3d24cf9a98df758)
Merge "Remove low-value logging from publication codepath" into stable/icehouse