Test for 'JAVA|' when determining if the App Service is a Java app

[wimdeblauwe]

This PR fixes https://issues.jenkins-ci.org/browse/JENKINS-63496

I tested this on our own Jenkins for deployment of a Spring Boot application to Azure App Service with this code in our Jenkinsfile:

dir('target') {
                    sh '''
                        cp myapp-backend-*.jar app.jar
                        '''
                    zip zipFile: 'app.zip', glob: 'app.jar'

                    azureWebAppPublish azureCredentialsId: 'JenkinsMyAppBackendServicePrincipal',
                            resourceGroup: 'MYAPP-BACKEND',
                            appName: 'myapp-backend-staging',
                            filePath: "app.zip"
                }