As an administrator, I want to use a predefined set of defaults for the OTLP server side indexing config when using LokiStack with tenant-mode openshift-logging, so that I can use validated and robust defaults.

Acceptance Criteria

1. Given the administrator creates a LokiStack resource with an empty limits spec, then LokiStack will provide a sane set of defaults for the otlp_config when the tenant mode is openshift-logging.
2. Given the administrator creates a LokiStack resource with an non-empty limits spec, then LokiStack will provide the merge set of otlp_config when the tenant mode is openshift-logging.

Developer Notes

1. The sane defaults are currently documented on the enhancement proposal.
2. We want to define a set of required set of attributes used in the loki config when tenant mode is openshift-logging.