title: cdkDragPreview and cdkDragPlaceholder not working as expected with horizontal elements
body: <p>I'm using display-inline in my elements as I want them to lay out horizontally instead of vertically as they do in most of the Angular examples.  That said, the CSS behaves very weird.  I'm specifically having two issues.  </p>
  
  <ol>
  <li>When I click an element to drag it, it grows (shrinks back to regular size after dropped).  I'm not sure exactly why this happens but it is definitely not desired.  I've tried numerous things to fix this via both css and adding a cdkDragPreview element with matchSize present (this seems to be the method Angular recommends).  All of those efforts failed.  I came across the following bug report that seems similar to my issue:  <a href="https://github.com/angular/components/issues/19060" rel="nofollow noreferrer">https://github.com/angular/components/issues/19060</a>.  I noted that the bug was closed, so I don't know if that means it has been fixed.  </li>
  <li>When I start to drag an element from the bottom drop list, the remaining items move around sporadically while that element is still in the drop list (when it goes out of the bottom drop list they behave as I would expect them to).  I created a hide style for the cdkDragPlaceholder as this seems to be how Angular provides control of this but it only helped with the top drop lists and seemed to have no effect on the bottom.  </li>
  </ol>
  
  <p>Here is a link that illustrates both issues on StackBlitz:  <a href="https://stackblitz.com/edit/spuzzler" rel="nofollow noreferrer">https://stackblitz.com/edit/spuzzler</a>.  I'm guessing that my issue can be fixed with CSS, but I can't figure out how.  </p>