manifests: add missing namespace on opentelemetry-demo-grafana-dashboards configmaps

[hsinhoyeh]

Changes

add missing namespace to opentelemetry-demo-grafana-dashboards configmaps

fixes: #1336

Merge Requirements

For new features contributions please make sure you have completed the following
essential items:

• CHANGELOG.md updated to document new feature additions
• Appropriate documentation updates in the docs
• Appropriate Helm chart updates in the helm-charts

Maintainers will not merge until the above have been completed. If you're unsure
which docs need to be changed ping the
@open-telemetry/demo-approvers.

[puckpuck]

This is a generated file from the Helm install. We need to figure out how to ensure we have the proper output while generating it.

make generate-kubernetes-manifests is what's used to generate the file.

[hsinhoyeh]

This is a generated file from the Helm install. We need to figure out how to ensure we have the proper output while generating it.

make generate-kubernetes-manifests is what's used to generate the file.

generate-kubernetes-manifests

ic, then the fix should be here: https://github.com/open-telemetry/opentelemetry-helm-charts/blob/main/charts/opentelemetry-demo/templates/grafana-dashboards.yaml#L5

[hsinhoyeh]

@puckpuck please check this patch on helm-chart https://github.com/open-telemetry/opentelemetry-helm-charts/pull/1002/files

then we can proceed update the generated manifests here after it has landed.