istio-agent: only send NDS if DNS is enabled (#28386)
istio-agent: only send NDS if DNS is enabled (#28386)

Signed-off-by: Xiang Dai <c54c64cf7043291b886753756d851be401eacd91@foxmail.com>
istio/istio,istio/istio,istio/istio,istio/istio,istio/istio