Files
wlan-cloud-helm/tip-wlan/charts/postgresql/files/conf.d

If you don't want to provide the whole configuration file and only specify certain parameters, you can copy here your extended .conf files. These files will be injected as a config maps and add/overwrite the default configuration using the include_dir directive that allows settings to be loaded from files other than the default postgresql.conf.

More info in the bitnami-docker-postgresql README.