After opening the Augumenta-AIP-SDK-examples-gradle-v2.5.0.zip you are getting this error:

  A problem occurred evaluating root project 'EXAMPLE_PROJECT'.
> Plugin with id 'com.android.application' not found.

To fix it, you need to go to: Files -> Project Structure -> Project and set the following values for: Android Gradle Plugin Version: type 4.0.1. Then select from the drop-down of Gradle Version and the version 6.1.1.

NOTE: This error might be caused if you tried to run the example modules as a root project. Please follow the steps from here: How to use the Android examples with Android Studio?.