title: How to change material-ui slider thumb style when it's disabled
body: <p>I am able to modify the <code>Slider</code> style using <code>withStyles</code>:</p>
  
  <pre><code>const CustomSlider = withStyles(theme =&gt; ({
    disabled: {
      color: theme.palette.primary.main
    },
    thumb: {
      height: 24,
      width: 24,
    },
  }))(Slider);
  </code></pre>
  
  <p>but the <code>height</code> and <code>width</code> of the thumb is only applied when the component is <code>disabled={false}</code>.</p>
  
  <p>is there a simple way to change the slider <code>height</code> and <code>width</code> on <code>disabled={true}</code>?</p>
  
  <p>Demo:
  <a href="https://codesandbox.io/s/slide-thumb-size-gxb4g?file=/demo.js" rel="noreferrer">https://codesandbox.io/s/slide-thumb-size-gxb4g?file=/demo.js</a></p>