delta-xds: avoid sending resource names for wildcard requests on stream reconnect (#16153)

Signed-off-by: Adi Suissa-Peleg <adip@google.com>

Mirrored from https://github.com/envoyproxy/envoy @ d86bd1140a53a32d7d5558af5be4ed778eaae179

xds_protocol.rst

@@ -771,10 +771,13 @@ Later the xDS client spontaneously requests the "wc" resource.
    :alt: Incremental session example
 
 On reconnect the Incremental xDS client may tell the server of its known
-resources to avoid resending them over the network. Because no state is
-assumed to be preserved from the previous stream, the reconnecting
-client must provide the server with all resource names it is interested
-in.
+resources to avoid resending them over the network by sending them in
+:ref:`initial_resource_versions <envoy_api_field_DeltaDiscoveryRequest.initial_resource_versions>`.
+Because no state is assumed to be preserved from the previous stream, the reconnecting
+client must provide the server with all resource names it is interested in. Note that for wildcard
+requests (CDS/LDS/SRDS), the request must have no resources in both
+:ref:`resource_names_subscribe <envoy_api_field_DeltaDiscoveryRequest.resource_names_subscribe>` and
+:ref:`resource_names_unsubscribe <envoy_api_field_DeltaDiscoveryRequest.resource_names_unsubscribe>`.
 
 .. figure:: diagrams/incremental-reconnect.svg
    :alt: Incremental reconnect example