tl;dr: When you are using Gerrit and Jenkins on the same machine, know what you're doing!
In a recent project we decided to increase code quality by introducing Gerrit as Code Review Tool.
The configuration looks as follows:
Next to a colleague who reviews the patchset, we created a dedicated Jenkins job which verfies the patchset by building the project with the usual maven build configuration “mvn clean install” on the same machine. Only when both the reviewer and the ci server accept the patchset, it will be merged into our git repository.