The configuration is located on
$GERRIT_SITE/etc/analytics.config and allows to customize the default parameters for the analytics extraction.
List of regexps that identify a bot-like commit, commits that modify only files whose name is a match will be flagged as bot-like.
[contributors] botlike-filename-regexp = .+\\.xml botlike-filename-regexp = .+\\.bzl botlike-filename-regexp = BUILD botlike-filename-regexp = WORKSPACE
Keep in mind that plugin configurations are written in git-config style syntax, so you should be escaping regular expressions accordingly.