avoid allocation for ASCII only

Author: ariksher-nex

sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/java/JavaGenerator.java

@@ -3291,8 +3291,14 @@ private void appendDecoderDisplay(
             }
             else
             {
-              //append(sb, indent, "builder.append('\\'' + " + varDataName + "() + '\\'');");
-                append(sb, indent, formatGetterName(varDataToken.name()) + "(builder);");
+                if (characterEncoding.contains("ASCII"))
+                {
+                    append(sb, indent, "builder.append('\\'');");
+                    append(sb, indent, formatGetterName(varDataToken.name()) + "(builder);");
+                    append(sb, indent, "builder.append('\\'');");
+                } else {
+                    append(sb, indent, "builder.append('\\'').append(" + varDataName + "()).append('\\'');");
+                }
             }
 
             lengthBeforeLastGeneratedSeparator = sb.length();