[elasticsearch] use bash to run scripts

elasticsearch/templates/statefulset.yaml

@@ -175,10 +175,9 @@ spec:
         image: "{{ .Values.image }}:{{ .Values.imageTag }}"
         imagePullPolicy: "{{ .Values.imagePullPolicy }}"
         command:
-        - sh
+        - bash
         - -c
         - |
-          #!/usr/bin/env bash
           set -euo pipefail
 
           elasticsearch-keystore create
@@ -227,10 +226,10 @@ spec:
         readinessProbe:
           exec:
             command:
-              - sh
+              - bash
               - -c
               - |
-                #!/usr/bin/env bash -e
+                set -e
 
                 # Exit if ELASTIC_PASSWORD in unset
                 if [ -z "${ELASTIC_PASSWORD}" ]; then