[FIXED JENKINS-16776] surefire-reports not detected for android-maven-plugin

I've confirmed that this fixes my problem. 

I used the following to confirm that getDirectory on the build is the right thing to use. The Maven docs are not clear whether it includes the full pathname but a post on stackoverflow confirms that it does. This matches with my observations in practice.

http://maven.apache.org/ref/3.0.4/maven-model/apidocs/org/apache/maven/model/BuildBase.html
http://stackoverflow.com/questions/9318935/get-project-build-directory-from-mavenproject