Automatic merge from submit-queue

fix: elasticsearch template mapping to parse kubernetes.labels

**What this PR does / why we need it**:

This PR updates the field mappings for the elasticsearch template that ships with the EFK stack implementation.

Specifically, elasticsearch cannot parse the `kubernetes.labels` object because it attempts to treat it as a string and produces an error. This update treats `kubernetes.labels` as an object and all of the properties within as a string, allowing accurate indexing and allowing users in kibana to search on `kubernetes.labels.*`.

**Release note**:
```release-note
Fluentd/Elastisearch add-on: correctly parse and index kubernetes labels
```