[OSO] templates builds OOMKilled on OSO

The quickstart templates fail on OpenShift Online Pro, as the build pod gets OOMKilled.

As the buildconfigs in the templates do not define any explicit memory resource limit, the default value of 512MiB is applied to the build pods. Maven allocates more than 1GiB during its run, so it is oomkilled.

The templates should define an explicit memory limit on the BuildConfigs (see https://docs.openshift.com/container-platform/3.5/dev_guide/builds/advanced_build_operations.html )

Also, an additional MAVEN_OPTS env could be added to the template and the buildconfig to limit the maven heap to some defined value.