6850806: NPE exception throws in PrintServce.getSupportedAttributeValues

Reviewed-by: igor, prr

src/windows/classes/sun/print/Win32PrintService.java

@@ -1325,7 +1325,7 @@ public class Win32PrintService implements PrintService, AttributeUpdater,
             }
             if (trays != null) {
                 System.arraycopy(trays, 0, arr,
-                                 mediaSizeNames.length, trays.length);
+                                 len - trays.length, trays.length);
             }
             return arr;
         } else if (category == MediaPrintableArea.class) {