Here is how you fix that.
In your file:
Make sure you have two settings in there
[Enable hibernate by default in upower]
[Enable hibernate by default in logind]
Here is why. In this file:
it sets the two options to "no"
The file you created should be executed after the one in /var/lib so it should take priority over it (Tested it and it does). You can read the information for that here under the section "Evaluation Order". When your "upower" option is set to "yes" you can select hibernate from the power settings in Ubuntu. However, you are still unable to hibernate because the 10-vendor.d file was setting the login1.hibernate to "no" and that must also be a "yes"