Error thrown by elasticsearch/index_summary metricset when xpack.enabled is set to true

[ycombinator]

Observed with Metricbeat built from master and Elasticsearch built from master.

Steps to reproduce

1. Make sure Elasticsearch API is accessible on http://localhost:9200.
2. Enable the elasticsearch-xpack Metricbeat module.

   ./metricbeat modules enable elasticsearch-xpack
   

3. Run Metricbeat.

   ./metricbeat -e
   

Observed behavior

The Metricbeat logs have the following error message:

2019-06-10T03:00:47.439-0700    ERROR   [elasticsearch.index_summary]   index_summary/index_summary.go:92       failure applying stats schema: 8 errors: key `total.docs` not found; key `total.store` not found; key `total.indexing` not found; key `total.search` not found; key `primaries.docs` not found; key `primaries.store` not found; key `primaries.indexing` not found; key `primaries.search` not found

No .monitoring-es-*mb* indices are created.

Expected behavior

No error in the Metricbeat logs and .monitoring-es-*mb* indices are created.

[elasticmachine]

Pinging @elastic/stack-monitoring