Restructure jvm metrics to match java client
Restructure jvm metrics to match java client

William-Yeh/es_cluster_exporter,jrummler/elasticsearch_exporter,ewr/elasticsearch_exporter,justwatchcom/elasticsearch_exporter,yackushevas/elasticsearch_exporter,Kuckkuck/elasticsearch_exporter,mattkanwisher/elasticsearch_exporter,rayhou/elasticsearch_exporter