Android framework-res.apk overlay

General information for the business: Android Application Developers
Num. of modules: 1
Description of every module: We currently need to override navigation_bar_height value from the framework-res.apk package. Based on Android documentation, this can be done by placing an apk in the system/vendor/overlay folder that will only contain the values that we wish to override. Once the system restarts, it will read the new values and use them to load the operating system.

We have found a sample project that we have followed, but haven’t been able to make it work. Please see the link below, it also has instructions on the page, and a lot of information can be found on the web for this override method.

Sample project: https://github.com/ReinhardStrauch/framework-res-overlay-sample

Requirements:
• Android 5.0 (Lollipop) or higher - Rooted.

Deliverable:
• The sample project working in both Lollipop and Marshmallow

I am willing to pay a bounty of $1500 to make this sample project work, and another $500 if you have a simpler method. FYI, just changing the value is not acceptable. Although you will need a rooted device to be able to test, the final version we will be preloading on a non rooted device.
Description of requirements/functionality: The sample project working in both Lollipop and Marshmallow
Extra notes: