[autotest] add additional logging to reimager and dynamic suite

This CL adds some additional logging to help trace SERVER_JOBs that are
getting stalled.

BUG=chromium:263387
TEST=Unit tests pass

Change-Id: I78860ad88bad3ef7346eeb174a09a2a6391ec106
Reviewed-on: https://gerrit.chromium.org/gerrit/63104
Tested-by: Aviv Keshet <akeshet@chromium.org>
Reviewed-by: Prashanth Balasubramanian <beeps@chromium.org>
Commit-Queue: Aviv Keshet <akeshet@chromium.org>
2 files changed