Print proxy status when debug fails for root cause (#7736)

tests/util/helpers.sh

@@ -57,6 +57,7 @@ _wait_for_istio() {
     local name="$3"
     if ! istioctl experimental wait --for=distribution --timeout=5m "$kind" "$name.$namespace"; then
         echo "Failed distribution of $kind $name in namespace $namespace"
+        istioctl ps
         exit 1
     fi
 }