Merge pull request #2698 from nextcloud/filedetailsharing-private-constructor

fragment:util: Added private constructor to hide the inherit public one

src/main/java/com/owncloud/android/ui/fragment/util/FileDetailSharingFragmentHelper.java

@@ -39,6 +39,10 @@ import java.util.Date;
  */
 public class FileDetailSharingFragmentHelper {
 
+    private FileDetailSharingFragmentHelper() {
+        // Private empty constructor
+    }
+
     /**
      * Sets checked/visiblity state on the given {@link MenuItem} based on the given criteria.
      *