Add support for Logstash' ephemeral_id (elastic/x-pack-elasticsearch#1697)
Add support for Logstash' ephemeral_id (elastic/x-pack-elasticsearch#1697)

Logstash now has ephemeral id at the instance level and also at the
pipeline level, we need to add them to the logstash monitoring template.

Original commit: elastic/x-pack-elasticsearch@dfac702d5937938dbeb9f01b186bd15ce6682e63

GlenRSmith/elasticsearch,HonzaKral/elasticsearch,strapdata/elassandra,scorpionvicky/elasticsearch,vroyer/elassandra,vroyer/elassandra,coding0011/elasticsearch,strapdata/elassandra,robin13/elasticsearch,scorpionvicky/elasticsearch,strapdata/elassandra,scorpionvicky/elasticsearch,robin13/elasticsearch,uschindler/elasticsearch,gingerwizard/elasticsearch,HonzaKral/elasticsearch,uschindler/elasticsearch,coding0011/elasticsearch,uschindler/elasticsearch,vroyer/elassandra,coding0011/elasticsearch,coding0011/elasticsearch,strapdata/elassandra,nknize/elasticsearch,scorpionvicky/elasticsearch,gfyoung/elasticsearch,nknize/elasticsearch,gingerwizard/elasticsearch,gfyoung/elasticsearch,gfyoung/elasticsearch,gfyoung/elasticsearch,GlenRSmith/elasticsearch,nknize/elasticsearch,GlenRSmith/elasticsearch,gingerwizard/elasticsearch,gingerwizard/elasticsearch,GlenRSmith/elasticsearch,gfyoung/elasticsearch,robin13/elasticsearch,strapdata/elassandra,gingerwizard/elasticsearch,HonzaKral/elasticsearch,uschindler/elasticsearch,gingerwizard/elasticsearch,nknize/elasticsearch,robin13/elasticsearch,uschindler/elasticsearch,GlenRSmith/elasticsearch,HonzaKral/elasticsearch,gingerwizard/elasticsearch,nknize/elasticsearch,scorpionvicky/elasticsearch,robin13/elasticsearch,coding0011/elasticsearch