Fix cpp string literal when next character is between [0-F] (#16245)

* Allow all characters with excape hex to be listeral string in C++

* Generated Code.

Author: Josh V [Apple]

src/app/zap-templates/common/ClusterTestGeneration.js

@@ -734,12 +734,9 @@ function octetStringEscapedForCLiteral(value)
   // Escape control characters, things outside the ASCII range, and single
   // quotes (because that's our string terminator).
   return value.replace(/\p{Control}|\P{ASCII}|"/gu, ch => {
-    let code = ch.charCodeAt(0);
-    code     = code.toString(16);
-    if (code.length == 1) {
-      code = "0" + code;
-    }
-    return "\\x" + code;
+    var code = ch.charCodeAt(0).toString(8)
+    return "\\" +
+        "0".repeat(3 - code.length) + code;
   });
 }