Modify Uploader activity to be singleton in the activity stack, and assure finish when the upload scheme is file

AndroidManifest.xml

@@ -71,7 +71,8 @@
             </intent-filter>
         </activity>
         <activity android:name=".ui.activity.UploadFilesActivity" />
-        <activity android:name=".ui.activity.Uploader" >
+        <activity android:name=".ui.activity.Uploader"
+                  android:launchMode="singleInstance">
             <intent-filter>
                 <action android:name="android.intent.action.SEND" />
 

src/com/owncloud/android/ui/activity/Uploader.java

@@ -569,6 +569,10 @@ public class Uploader extends FileActivity
             .getDefaultSharedPreferences(getApplicationContext()).edit();
         appPrefs.putString("last_upload_path", mUploadPath);
         appPrefs.apply();
+
+        if(contentUris.isEmpty()) {
+            finish();
+        }
     }
 
     /**