Do not launch a quick viewer unless it's whitelisted.

        String trustedPkg = mResources.getString(R.string.trusted_quick_viewer_package);

        if (!TextUtils.isEmpty(trustedPkg)) {

            Intent intent = new Intent(Intent.ACTION_QUICK_VIEW);

            intent.setDataAndType(mDocument.derivedUri, mDocument.mimeType);

            intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);

        if (TextUtils.isEmpty(trustedPkg)) {

            if (hasRegisteredHandler(intent)) {

                return intent;

            }

        } else {

            intent.setPackage(trustedPkg);

            if (hasRegisteredHandler(intent)) {

                // We have a trusted handler. Load all of the docs into the intent.

                Cursor cursor = mSiblings.getCursor();

                for (int i = 0; i < cursor.getCount(); i++) {

                    onNextItem(i, cursor);