I have tried every method to lock the screen to portrait orientation but they simply do not work after testing the app via Adobe PhoneGap Build.
Firstly, I have modified the MainActivity.java file to include at onCreate
<preference name="orientation" value="portrait" />
If you're using Cordova 3.4.1
<preference name="orientation" value="portrait" /> should work.
Also, don't forget to add:
android:configChanges="orientation" in the activity tag.
Else, you can try using this plugin: https://github.com/cogitor/PhoneGap-OrientationLock