Fix image repo value for managed_otlp onboarding config

Author: ebeahan

deploy/helm/edot-collector/kube-stack/managed_otlp/values.yaml

@@ -16,7 +16,7 @@ crds:
  create: true # Install the OpenTelemetry Operator CRDs.
 defaultCRConfig:
  image:
- repository: "docker.elastic.co/beats/elastic-agent"
+ repository: "docker.elastic.co/elastic-agent/elastic-agent"
  tag: "9.1.0"
  targetAllocator:
  enabled: false # Enable/disable the Operator's Target allocator.