Add query for heat slow icehouse timeout bug 1374175

The timeout error message for this bug was recently
updated to give more context to the test that's failing,
so the current hits in logstash are low, but this is
hitting and appears to show up on the tempest dvsm
neutron heat slow icehouse job.

Change-Id: I3c973e0b28fcf32f178b57d41b6be2466fadf836
Related-Bug: #1374175
Merge "Add query for heat slow icehouse timeout bug 1374175"