[Watcher] Use auto_expand_replicas on triggered_watches index too (elastic/x-pack-elasticsearch#3371)
[Watcher] Use auto_expand_replicas on triggered_watches index too (elastic/x-pack-elasticsearch#3371)

In the previous pass, only the ".watch*" templates were impacted. This also should use `auto_expand_replicas`.

Original commit: elastic/x-pack-elasticsearch@bcaad6cf2ef3610d79f7ae1cb453b1d849779f2d

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