8313087: DerValue::toString should output a hex view of the values in byte array

Reviewed-by: mullan

src/java.base/share/classes/sun/security/util/DerValue.java

@@ -1133,7 +1133,8 @@ public class DerValue {
     @Override
     public String toString() {
         return String.format("DerValue(%02x, %s, %d, %d)",
-                0xff & tag, buffer, start, end);
+                0xff & tag, HexFormat.of().withUpperCase().formatHex(buffer),
+                start, end);
     }
 
     /**