This PR will make it easier for future Flutter-Android apps/plugins/modules etc. to migrate to Gradle Kotlin DSL.

This PR is similar to #140452 but concerns public Gradle templates instead of Flutter's internal Gradle code. It should be a no-op change.

**before**

![before](https://github.com/flutter/flutter/assets/40357511/5d0cb2bb-a693-43bc-aa10-b8f431e0c68c)

**after**

![after](https://github.com/flutter/flutter/assets/40357511/e4a945a5-866f-42f7-813b-b08b26bb89dc)