Since Flutter 3.29, new projects will use the Kotin gradle DSL.
Files like build.gradle and settings.gradle now have a .gradle.kts extension.

Besides the file extension change, the syntax is different.

For example:

- implementation project(':unityLibrary')
+ implementation(project(":unityLibrary"))

flatDir {
-    dirs "${project(':unityLibrary').projectDir}/libs"
+    dirs(file("${project(":unityLibrary").projectDir}/libs"))
}

This PR adds this new syntax as alternative code blocks in the README.

To reproduce and test this:

• delete android folder of the example.
• Regenerate it with Flutter 3.29 by running

flutter create --org=com.learntoflutter. --project-name=flutter_embed_unity_example

• Follow the new readme for .gradle.kts files
• export unity
• build the flutter example
• Follow any flutter build error instructions. In my case:
  • set minsdk to 22 in app/build.gradle
  • remove ndkPath from unitylibary/build.gradle
  • set ndkVersion to "27.0.12077973" in app/build.gradle
• example now runs with Flutter 3.29 gradle setup.