cleanup: clarify Cluster.filters and Dispatcher::createClientConnection (#8186)

Signed-off-by: Fred Douglas <fredlas@google.com>

Mirrored from https://github.com/envoyproxy/envoy @ 9de651a4de6ca162d0c7fbd596b3b138c99ce05f

envoy/api/v2/cds.proto

@@ -647,9 +647,9 @@ message Cluster {
   // checking before removing it from the cluster.
   bool drain_connections_on_host_removal = 32;
 
-  // An optional list of network filters that make up the filter chain for
-  // outgoing connections made by the cluster. Order matters as the filters are
-  // processed sequentially as connection events happen.
+  // An (optional) network filter chain, listed in the order the filters should be applied.
+  // The chain will be applied to all outgoing connections that Envoy makes to the upstream
+  // servers of this cluster.
   repeated cluster.Filter filters = 40;
 
   // [#not-implemented-hide:] New mechanism for LB policy configuration. Used only if the

envoy/api/v3alpha/cds.proto

@@ -634,9 +634,9 @@ message Cluster {
   // checking before removing it from the cluster.
   bool drain_connections_on_host_removal = 32;
 
-  // An optional list of network filters that make up the filter chain for
-  // outgoing connections made by the cluster. Order matters as the filters are
-  // processed sequentially as connection events happen.
+  // An (optional) network filter chain, listed in the order the filters should be applied.
+  // The chain will be applied to all outgoing connections that Envoy makes to the upstream
+  // servers of this cluster.
   repeated cluster.Filter filters = 40;
 }