The readme has instructions how to configure eclipse or intellij to format XML for 2 spaces (and both tools support reformatting a part of a file IIIRC). Normally you can set that on a per project basis.
https://github.com/droolsjbpm/droolsjbpm-build-bootstrap/blob/master/README.md#developing-with-eclipse
(note that in eclipse the xml indentation setting is in a very strange place, not in the code style).