Graph components of Elasticsearch health

Graph things like the number of active shards, unassigned shards, and
relocating shards.  These graphs are the same for every node on the cluster
but at least we'll have graphs of them.  Rather, they should be the same
for all nodes on the cluster.  If they aren't that implies a split brain
which implies that updates aren't going to be recorded properly.

Bug: 57244
Change-Id: Ib1fa44bf9954dc187d8ee56fa6c265b9136d9994