Merge "Revert "Revert "Enable manage mode for ExternalStorageProvider when...

    @Override

    public boolean managedModeEnabled(DocumentStack stack) {

        // This method helps us understand when to kick in special manage mode behaviors.

        final RootInfo root = stack.getRoot();

        // When in Files activity, allow External Storage provider to view

        // Android/[data|obb|sandbox] directories which are otherwise hidden for privacy reasons.

        if (root != null && root.isExternalStorage()) {

            return true;

        }

        // When in downloads top level directory, we also show active downloads.

        // And while we don't allow folders in Downloads, we do allow Zip files in

        // downloads that themselves can be opened and viewed like directories.

        // This method helps us understand when to kick in on those special behaviors.

        final RootInfo root = stack.getRoot();

        return root != null

                && root.isDownloads()

                && stack.size() == 1;