Set missing variables (#33)

Author: petetomasik

scripts/user-data-linux.sh

@@ -83,6 +83,9 @@ ECR_CREDENTIAL_HELPER_ENABLED="${enable_ecr_credential_helper}" \
 DOCKER_LOGIN_PLUGIN_ENABLED="${enable_docker_login_plugin}" \
 DOCKER_EXPERIMENTAL="${enable_docker_experimental}" \
 DOCKER_USERNS_REMAP=${enable_docker_userns_remap} \
+DOCKER_PRUNE_UNTIL=${docker_prune_until} \
+ENABLE_PRE_EXIT_DISK_CLEANUP=${enable_pre_exit_disk_cleanup} \
+DOCKER_BUILDER_PRUNE_ENABLED=${docker_builder_prune_enabled} \
 AWS_REGION="${aws_region}" \
 ENABLE_RESOURCE_LIMITS="${enable_resource_limits}" \
 RESOURCE_LIMITS_MEMORY_HIGH="${resource_limits_memory_high}" \