[ISSUE #8906] Handle string toUpperCase outside the loop

Author: mawen12

proxy/src/main/java/org/apache/rocketmq/proxy/remoting/MultiProtocolTlsHelper.java

@@ -102,8 +102,9 @@ private static ClientAuth parseClientAuthMode(String authMode) {
             return ClientAuth.NONE;
         }
 
+        String authModeUpper = authMode.toUpperCase();
         for (ClientAuth clientAuth : ClientAuth.values()) {
-            if (clientAuth.name().equals(authMode.toUpperCase())) {
+            if (clientAuth.name().equals(authModeUpper)) {
                 return clientAuth;
             }
         }

remoting/src/main/java/org/apache/rocketmq/remoting/netty/TlsHelper.java

@@ -216,8 +216,9 @@ private static ClientAuth parseClientAuthMode(String authMode) {
             return ClientAuth.NONE;
         }
 
+        String authModeUpper = authMode.toUpperCase();
         for (ClientAuth clientAuth : ClientAuth.values()) {
-            if (clientAuth.name().equals(authMode.toUpperCase())) {
+            if (clientAuth.name().equals(authModeUpper)) {
                 return clientAuth;
             }
         }