[BUG][opensearch] Wrong indentation on env and envfrom when using keystore value

[PaulLesur]

Describe the bug
When using keystore value I get an invalid YAML error :

Error: YAML parse error on opensearch/charts/opensearch/templates/statefulset.yaml: error converting YAML to JSON: yaml: line 108: could not find expected ':'

To Reproduce
Steps to reproduce the behavior:

1. Use the keystore value
2. helm template
3. See error

Expected behavior
No error should be thrown and templating should be a successs.

Chart Name
opensearch

Screenshots
Not Applicable.

Host/Environment (please complete the following information):

• Helm Version: 3.4.2
• Kubernetes Version: 1.20.7

Additional context
I made a PR to resolve this issue : #103