Another try fixing buildkite

Author: breskeby

.buildkite/pipelines/periodic-java-ea.yml

@@ -512,7 +512,7 @@ steps:
           machineType: n1-standard-32
           buildDirectory: /dev/shm/bk
         env:
-          GRADLE_PARAMS: "-Druntime.java=$$JAVA_EA_VERSION"
+          GRADLE_PARAMS: "-Druntime.java=${JAVA_EA_VERSION}"
           GRADLE_TASK: "{{matrix.GRADLE_TASK}}"
       - label: "{{matrix.BWC_VERSION}} / matrix-bwc"
         command: .ci/scripts/run-gradle.sh -Druntime.java=$$JAVA_EA_VERSION  -Dbwc.checkout.align=true v$$BWC_VERSION#bwcTest