Log Message:
Update devel/gradle to 4.1.

Gradle 4.1

- Worker API for safe, concurrent work execution
- Build cache improvements
- Improved Composite Builds
- Console displays parallel test execution

  https://docs.gradle.org/4.1/release-notes.html

Gradle 4.0

- Parallel download of dependencies
- Build cache improvements
- Public type for representing lazily evaluated properties
- Configurable input normalization
- Convenience method for adding Google repository
- User experience improvements

  https://docs.gradle.org/4.0/release-notes.html

Gradle 3.5

- Faster builds with the Gradle Build Cache
- Console with a build summary and more detailed work-in-progress
- Kotlin Build Scripts
- Plugin resolution rules

  https://docs.gradle.org/3.5/release-notes.html