Should verify application property and pass the verified value through to the deploy step.
If "deploy.read.appengine.web.xml" system property is set, make sure project id is only set in appengine-web.xml and not build config, otherwise error.
If "deploy.read.appengine.web.xml" is not set, then make sure project id is set in build config, otherwise error.
Should verify application property and pass the verified value through to the deploy step.