LPS-42846  After moving a document between folders with Amazon s3 DL Store the document cannot be downloaded

Hey Hugo,

The issue is that a trailing slash was removed from the getKey method which in turn breaks this functionality. The document is stored with a key of "1/10815/301/1.0" but Liferay tries to search for "1/10815301/1.0" instead. This fix adds the slash back in but still preserves the fix from LPS-31081.

Also, on line 385, there is a duplicate "x = oldKey.indexOf(CharPool.SLASH, x + 1);". I wasn't sure if that was there on purpose so I just left it in but wanted to get your thoughts on it.

Thanks.