Disable Gradle daemon for Gradle Gitlab CI template

It's recommended to disable Gradle daemon for Continuous Integration servers as correctness is usually a priority over speed in CI environments. Official documentation link: Continuous Integration section. But unfortunately the Gradle Daemon is enabled by default starting with Gradle 3.0 (good for developers, not optimal for CI).

So I use for my projects the following snippet in .gitlab-ci.yml to disable Gradle daemon:

variables:
  GRADLE_OPTS: "-Dorg.gradle.daemon=false"

MR will come.