[BUG][Opensearch] Keystore init container exits with error

[smlx]

Describe the bug
The keystore init container doesn't work because the opensearch-keystore binary is not in $PATH.

To Reproduce
Steps to reproduce the behavior:

1. Configure some keystore values in the chart values.
2. Apply the chart.
3. See error in init container.

Expected behavior
Specified values should be added to the keystore.

Chart Name
Opensearch.

Screenshots
n/a

Host/Environment (please complete the following information):

• Helm Version: v3.6.2
• Kubernetes Version: 1.20.7

Additional context
n/a