MB-8121: show usages for enabling flush and index replica
MB-8121: show usages for enabling flush and index replica

Change-Id: Ibf7b6a72566a21f44ce4b0f2c11d950ef4e2fb45

couchbaselabs/couchbase-cli,couchbase/couchbase-cli,couchbase/couchbase-cli,couchbaselabs/couchbase-cli,couchbaselabs/couchbase-cli