fix(client-java): repair illegal unicode escape in MxGatewayCliTests comment

Same \u-in-comment issue as the production file (MxGatewayCliTests.java:69).
Reworded to plain ASCII. Scanned all agent-touched Java files; no other stray
unicode-escape sequences remain.

clients/java/zb-mom-ww-mxgateway-cli/src/test/java/com/zb/mom/ww/mxgateway/cli/MxGatewayCliTests.java

@@ -63,10 +63,10 @@ final class MxGatewayCliTests {
 
     @Test
     void jsonStringEscapesControlCharacters() {
-        // Client.Java-041 — the hand-rolled jsonString escaped only \\ \" \r \n,
-        // so a tab/backspace/form-feed or any other control char produced
-        // malformed JSON (RFC 8259). After the fix the named control chars use
-        // their two-character escapes and the rest use \u00XX.
+        // Client.Java-041 — the hand-rolled jsonString escaped only backslash,
+        // quote, CR, and LF, so a tab/backspace/form-feed or any other control
+        // char produced malformed JSON (RFC 8259). After the fix the named control
+        // chars use their two-character escapes and the rest use six-char uXXXX.
         assertEquals("\"a\\tb\"", MxGatewayCli.jsonString("a\tb"));
         assertEquals("\"a\\bb\"", MxGatewayCli.jsonString("a\bb"));
         assertEquals("\"a\\fb\"", MxGatewayCli.jsonString("a\fb"));