[CI] Fix example-plugins tests by patching java home (elastic#138495)

Older version of openjdk17 are incompatible with newer ubuntu versions.
On ubuntu24 we now replace openjdk17 with adoptopenjdk17 in these cases.

Author: jozala

.buildkite/pipelines/periodic.template.yml

@@ -30,9 +30,7 @@ steps:
 
   - label: example-plugins
     command: |-
-      cd $$WORKSPACE/plugins/examples
-
-      $$WORKSPACE/.ci/scripts/run-gradle.sh build
+      ./.ci/scripts/example-plugins.sh build
     timeout_in_minutes: 300
     agents:
       provider: gcp

.buildkite/pipelines/periodic.yml

@@ -753,9 +753,7 @@ steps:
 
   - label: example-plugins
     command: |-
-      cd $$WORKSPACE/plugins/examples
-
-      $$WORKSPACE/.ci/scripts/run-gradle.sh build
+      ./.ci/scripts/example-plugins.sh build
     timeout_in_minutes: 300
     agents:
       provider: gcp

.buildkite/pipelines/pull-request/example-plugins.yml

@@ -7,9 +7,7 @@ config:
 steps:
   - label: example-plugins
     command: |-
-      cd $$WORKSPACE/plugins/examples
-
-      $$WORKSPACE/.ci/scripts/run-gradle.sh -Dorg.gradle.jvmargs=-Xmx8g build --include-build $$WORKSPACE
+      ./.ci/scripts/example-plugins.sh -Dorg.gradle.jvmargs=-Xmx8g build --include-build $$WORKSPACE
     timeout_in_minutes: 300
     agents:
       provider: gcp

.ci/scripts/example-plugins.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+
+set -euo pipefail
+
+# Older versions of openjdk are incompatible to newer kernel of ubuntu. Use adoptopenjdk17 instead
+resolve_java_home() {
+  if [[ "$ES_BUILD_JAVA" == *"openjdk17"* ]]; then
+    if [ -f "/etc/os-release" ]; then
+        . /etc/os-release
+        if [[ "$ID" == "ubuntu" && "$VERSION_ID" == "24.04" ]]; then
+          echo "$HOME/.java/adoptopenjdk17"
+          return
+        fi
+      fi
+  fi
+
+  echo "$JAVA_HOME"
+}
+
+cd $WORKSPACE/plugins/examples
+
+JAVA_HOME=$(resolve_java_home) \
+  $WORKSPACE/.ci/scripts/run-gradle.sh $@