Revert "Disable debug messages when running unit tests"

This reverts commit 56edda0d1840da1ccfcd7c35df397251ddb779db.

Another patch (commit-id: df96a03e6c74f1fceb4525900bca885307907b79) to
fix the same issue with less intrusive consequences was already merged
into master. There's still benefit to have debug logs if this does not
make gate jobs fail, so revert to previous setting value.

Related-Bug: 1316610
Change-Id: I9b57369027e1e43bed1bde4d971dee9fb7a26a47
Merge "Revert "Disable debug messages when running unit tests""