ElasticSearch container doesn't take into account the ES_INSTANCE_RAM environment variable to set -Xmx

Issue

Setting the ES_INSTANCE_RAM and/or ES_HEAP_SIZE during the EFK stack deployment doesn't make any difference in the size of the java heap for the ElasticSearch instance.

e.g.
- Set the ES_INSTANCE_RAM=1G during the deployment, then set the ES_HEAP_SIZE to 800M withing the Elastic Search DC:

[root@master ~]# oc env pods logging-es-sfucu3gp-5-nuy6z --list
# pods logging-es-sfucu3gp-5-nuy6z, container elasticsearch
KUBERNETES_TRUST_CERT=true
SERVICE_DNS=logging-es-cluster
CLUSTER_NAME=logging-es
INSTANCE_RAM=1G
NODE_QUORUM=1
RECOVER_AFTER_NODES=0
RECOVER_EXPECTED_NODES=1
RECOVER_AFTER_TIME=5m
ES_HEAP_SIZE=800M
[root@master ~]#