trigger indexing of file after operation (#1498)

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/ExportHelper.java

@@ -20,6 +20,8 @@ package org.sufficientlysecure.keychain.util;
 
 import java.io.File;
 
+import android.content.Intent;
+import android.net.Uri;
 import android.support.v4.app.FragmentActivity;
 
 import org.sufficientlysecure.keychain.Constants;
@@ -98,7 +100,10 @@ public class ExportHelper
     }
 
     @Override
-    public void onCryptoOperationSuccess(ExportResult result) {
+    final public void onCryptoOperationSuccess(ExportResult result) {
+        // trigger scan of the created 'media' file so it shows up on MTP
+        // http://stackoverflow.com/questions/13737261/nexus-4-not-showing-files-via-mtp
+        mActivity.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(mExportFile)));
         result.createNotify(mActivity).show();
     }