Description of the issue:

The v1beta1 API expects {} to be added for empty objects. If a collector instance is created without the empty {}, the collector throws the following error which is not helpful for debugging. 

admission webhook "mopentelemetrycollectorbeta.kb.io" denied the request: src and dst must not be nil

We should improve the error message to point to the actual issue of missing {}

For more details refer issue https://github.com/open-telemetry/opentelemetry-operator/issues/3452