Example fix: dynamic heap size is not recommend (#2553)

Elastic recommends setting the same value for xms and xmx. The example therefor might be confusing.

See: https://www.elastic.co/guide/en/elasticsearch/reference/current/heap-size.html

Elasticsearch will assign the entire heap specified in jvm.options via the Xms (minimum heap size) and Xmx (maximum heap size) settings. You should set these two settings to be equal to each other.

docs/elasticsearch-specification.asciidoc

@@ -54,7 +54,7 @@ If you need to set resource requests and limits, see link:k8s-managing-compute-r
 
 Or if you want to install additional plugins, see <<{p}-init-containers-plugin-downloads>>.
 
-You might want to set environment variables to configure Elasticsearch. For example, to set the minimum and maximum JVM heap size to `2g` and `4g` respectively, you can modify the environment variables of the `elasticsearch` container as follows:
+You might want to set environment variables to configure Elasticsearch. For example, to set the JVM heap size to `4g`, you can modify the environment variables of the `elasticsearch` container as follows:
 
 [source,yaml]
 ----
@@ -68,7 +68,7 @@ spec:
         - name: elasticsearch
           env:
           - name: ES_JAVA_OPTS
-            value: "-Xms2g -Xmx4g"
+            value: "-Xms4g -Xmx4g"
 ----
 
 For more information on Pod templates, see the Kubernetes documentation: