title: Ag-grid RowStyle with selected row
body: <p>I am using ag-grid 5.1.2
  I've configured a getRowStyle function to set the background-color for certain items.</p>
  <p>I've noticed that has overridden the 'selected row' color now, so when a row is selected the background will not change to indicate as such.<br>What is the correct way to still let highlighted row color work with the custom getRowStyle.<br><br>  Here is the typescript for the rowStyle function:</p>
  <pre class="lang-js prettyprint-override"><code>self.customRowStyle = function (params: AgParams) {
    if (!params.data.isShaded) {
      return {
        &quot;background-color&quot;: &quot;#CEDDDD&quot;,
      };
    }
    return null;
  };
  
  </code></pre>