Automate javax/swing/border/Test4129681.java

The javax/swing/border/Test4129681.java test has a potential to be automatic test.

The test verifies whether the title in a titled border associated with a disabled component renders using disabled colors.

If you render JLabel into a BufferedImage or take a screenshot, you can analyse the color of the pixels, especially if you turn off text antialising.

Instead of real text, you can use a full block character: "█" (U+2588) which will make analysing the pixel colors more robust.