Automatic versioning of Android build using git describe with Gradle

I have searched extensively, but likely due to the newness of Android Studio and Gradle. I haven't found any description of how to do this. I want to do basically exactly what is described in this post, but with Android Studio, Gradle and Windows rather than Eclipse and Linux.

A more proper and lean way to achieve the result which gained traction lately would be to use grgit integration, which uses JGit Java libray. As it uses JGit it doesn't even require git to be installed to work (which simplifies things in build pipelines).

Here's a basic example showing a similar (but with some additional information in gitVersionName string) solution:

plugins {
  id 'org.ajoberstar.grgit' version '4.1.1'
}
ext {
  gitVersionCode = grgit.tag.list().size()
  gitVersionName = grgit.describe(tags: true, always: true)
}
android {
  defaultConfig {
    versionCode gitVersionCode
    versionName gitVersionName
  }
}
[...]

As you can see in Grgit API documentation the describe operation provides additional information other than most recent tag reachable in history:

Find the most recent tag that is reachable from HEAD. If the tag points to the commit, then only the tag is shown. Otherwise, it suffixes the tag name with the number of additional commits on top of the tagged object and the abbreviated object name of the most recent commit.

Anyhow, it won't tell if the state is dirty or not. This information can be easily added by looking at the clean status of the repo, and appending a string if it's not clean.