Update Gradle stage in Jenkinsfile

Jenkinsfile

@@ -3,7 +3,13 @@ pipeline {
     stages {
         stage('Gradle') {
             steps {
-                sh 'bash gradlew build'
+                withCredentials([usernamePassword(credentialsId: 'alttd-snapshot-user', usernameVariable: 'USERNAME', passwordVariable: 'PASSWORD')]) {
+                sh '''
+                  set +x
+                  chmod +x gradlew
+                  ./gradlew build -PalttdSnapshotUsername=$USERNAME -PalttdSnapshotPassword=$PASSWORD
+                '''
+                }
             }
         }
         stage('Archive') {