Limit BWC periodic job to compatible CI worker

.ci/jobs.t/elastic+elasticsearch+periodic+bwc.yml

@@ -1,9 +1,34 @@
 ---
-jjbb-template: matrix-gradle-unix.yml
-vars:
-  - job-name: elastic+elasticsearch+%BRANCH%+periodic+bwc
-  - job-display-name: "elastic / elasticsearch # %BRANCH% - backwards compatibility matrix"
-  - job-description: "Testing of the Elasticsearch %BRANCH% branch backwards compatibility matrix.\n"
-  - matrix-yaml-file: ".ci/bwcVersions"
-  - matrix-variable: BWC_VERSION
-  - gradle-args: "-Dbwc.checkout.align=true v$BWC_VERSION#bwcTest"
+- job:
+    name: elastic+elasticsearch+%BRANCH%+periodic+bwc
+    display-name: "elastic / elasticsearch # %BRANCH% - backwards compatibility matrix"
+    description: "Testing of the Elasticsearch %BRANCH% branch backwards compatibility matrix.\n"
+    project-type: matrix
+    child-workspace: /dev/shm/elastic+elasticsearch+%BRANCH%+periodic+bwc
+    node: master
+    scm:
+      - git:
+          wipe-workspace: false
+    axes:
+      - axis:
+          type: slave
+          name: nodes
+          values:
+            # Some of the versions 6.8 is compatible with do not work on cgroups2 so we pick a platform
+            # that doesn't come with it.
+            - "centos-7&&immutable"
+      - axis:
+          type: yaml
+          filename: ".ci/bwcVersions"
+          name: "BWC_VERSION"
+    builders:
+      - inject:
+          properties-file: '.ci/java-versions.properties'
+          properties-content: |
+            JAVA_HOME=$HOME/.java/$ES_BUILD_JAVA
+            RUNTIME_JAVA_HOME=$HOME/.java/$ES_RUNTIME_JAVA
+            JAVA11_HOME=$HOME/.java/java11
+            JAVA15_HOME=$HOME/.java/openjdk15
+      - shell: |
+          #!/usr/local/bin/runbld --redirect-stderr
+          $WORKSPACE/.ci/scripts/run-gradle.sh -Dbwc.checkout.align=true v$BWC_VERSION#bwcTest