better cert configuration

Signed-off-by: Wei Weng <Wei.Weng@microsoft.com>

Author: Wei Weng

charts/hub-agent/templates/certificate.yaml

@@ -40,15 +40,14 @@ spec:
 
   # Private key configuration
   privateKey:
-    algorithm: RSA
-    size: 4096
+    algorithm: ECDSA
+    size: 256
 
   # Key usages
   usages:
     - digital signature
     - key encipherment
     - server auth
-    - client auth
 ---
 # Self-signed issuer for generating the certificate
 apiVersion: cert-manager.io/v1