* Only kill local Gradle processes (classpath in checkout directory).
         * Not clean up global Gradle processes (i.e. classpath in ~/.gradle/...).
         * Because the step is not guaranteed to run (e.g. build timeout), we need `KILL_LEAKED_PROCESSES_FROM_PREVIOUS_BUILDS` mode.
         */
        KILL_PROCESSES_STARTED_BY_GRADLE,
        /**
         * Run when we want to retry the build. Kill all Gradle processes, regardless of they're global or local.