pass var prod_instance_id from prep-deploy to production-deploy

.gitlab-ci.yml

@@ -68,6 +68,8 @@ prep-deploy:
       echo "TF_VAR_data_volume=${TF_VAR_data_volume}" | tee -a $CI_PROJECT_DIR/vars.env
       echo "TF_VAR_flavor=${TF_VAR_flavor}" | tee -a $CI_PROJECT_DIR/vars.env
       echo "BUILD_DATE=${BUILD_DATE}" | tee -a $CI_PROJECT_DIR/vars.env
+      echo "prod_instance_id=${prod_instance_id}" | tee -a $CI_PROJECT_DIR/vars.env
+
   artifacts:
     reports:
       dotenv: vars.env