Exclude virtual files from ACTION_SEND.

            void onDocumentsReady(List<DocumentInfo> docs) {

                Intent intent;

                // Filter out directories - those can't be shared.

                // Filter out directories and virtual files - those can't be shared.

                List<DocumentInfo> docsForSend = new ArrayList<>();

                for (DocumentInfo doc: docs) {

                    if (!Document.MIME_TYPE_DIR.equals(doc.mimeType)) {

                    if (!doc.isDirectory() && !doc.isVirtualDocument()) {

                        docsForSend.add(doc);

                    }

                }