title: Removing placeholder for drop area when cursor not in drop zone in material cdk drag & drop
body: <p>When drag item moves over the drop area, the area is highlighted and created a placeholder for the same. But if the mouse point is moving away the drop area and release the drop the item. It still drop into the drop zone.</p>
  
  <p><a href="https://i.stack.imgur.com/LeGbE.gif" rel="nofollow noreferrer">Drag Drop Issue Demo</a></p>
  
  <p><strong>Expected behavior</strong>:</p>
  
  <p>Once the mouse pointer is move away from the drop zone and the user release the mouse or cancel the drag. It should go back to the drag start list.</p>
  
  <p><a href="https://stackblitz.com/angular/qxxnargngbb?file=app%2Fcdk-drag-drop-connected-sorting-example.ts" rel="nofollow noreferrer">stackblitz</a></p>