Docs: Fix watcher stats parameter names (elastic/x-pack-elasticsearch#4045)
Docs: Fix watcher stats parameter names (elastic/x-pack-elasticsearch#4045)

This fixes the (unfortunately super inconsistent) names for the watcher
stats REST tests in the docs.

relates elastic/x-pack-elasticsearch#236

Original commit: elastic/x-pack-elasticsearch@c382c5ea14797d5bcdbc80cce2afca400f19df5a

vroyer/elassandra,strapdata/elassandra,strapdata/elassandra,vroyer/elassandra,strapdata/elassandra,strapdata/elassandra,vroyer/elassandra,strapdata/elassandra