Nudge Kokoro

iot/api-client/mqtt_example/README.md

@@ -23,7 +23,7 @@ The following command summarizes the sample usage:
                      -registry_id=my-registry \
                      -device_id=my-device \
                      -private_key_file=rsa_private_pkcs8 \
-                     -algorithm=RS256"
+                     -algorithm=ES256"
 
 For example, if your project ID is `blue-jet-123`, your service account
 credentials are stored in your home folder in creds.json and you have generated