Added write_external_storage permission so non-rooted device are able to export

Author: rorist

AndroidManifest.xml

@@ -32,5 +32,6 @@
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
     <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
     <uses-permission android:name="android.permission.VIBRATE" />
 </manifest>