[BUG][opensearch] CrashLoop when keystore secret has data but script can't create keystore

[hm2thr33]

Describe the bug When the key store secret is configured and has entries in it, the shell script imports it incorrectly.

To Reproduce Steps to reproduce the behavior:

1. Create a Kubernetes Keystore Secret:

   apiVersion: v1
   kind: Secret
   metadata:
   name: keystore-secrets
   type: Opaque
   data:
   s3.client.default.access_key: foo
   s3.client.default.secret_key: bar

2. Configure a keystore secret in value.yml

   keystore:
   - secretName: keystore-secrets

3. Deploy the chart and observe CrashLoop from the keystore init container logs:

   Created opensearch keystore in /usr/share/opensearch/config/opensearch.keystore
   sh: line 6: file: unbound variable

   Expected behavior No CrashLoop

Chart Name Opensearch

Screenshots N/A

Host/Environment (please complete the following information):

• Helm Version: [3.12.1]
• Kubernetes Version: [1.22.15]
• OpenSearch Helm Chart version [2.13.2]

Additional context From my side any updates of value.yml files only pull of new version of helm chart https://github.com/opensearch-project/helm-charts/commit/4e4f82672f79704b38ae9063ea6c67655dd7a101

Temporary reverted my cluster configuration to OpenSearch Helm Chart version [2.13.1]

[prudhvigodithi]

Closing this as the fix has been pushed through the PR https://github.com/opensearch-project/helm-charts/pull/445, thanks to @hobti01 and @uncycler.