[IcebergIO] Run xlang wrapper validation expansion service on Java 17

The cross-language wrapper validation launches the io expansion-service jar from Python via JAVA_HOME. That jar bundles IcebergIO, now Java 17 bytecode, so launching it on the default Java 11 fails with UnsupportedClassVersionError.

createCrossLanguageUsingJavaExpansionTask was missing the JAVA_HOME redirect that #38974 added to the other cross-language task factories. Add it, driven by -PtestJavaVersion (resolving java\Home), and pass -PtestJavaVersion=17 in the Xlang_Generated_Transforms precommit so the expansion service runs on a JDK that can load the bundled Java 17 IOs.

Author: peterphitran

.github/workflows/beam_PreCommit_Xlang_Generated_Transforms.yml

@@ -117,4 +117,5 @@ jobs:
         with:
           gradle-command: :sdks:python:test-suites:direct:crossLanguageWrapperValidationPreCommit --info
           arguments: |
+            -PtestJavaVersion=17
             -Pjava17Home=$JAVA_HOME_17_X64

buildSrc/src/main/groovy/org/apache/beam/gradle/BeamModulePlugin.groovy

@@ -2721,6 +2721,11 @@ class BeamModulePlugin implements Plugin<Project> {
       def usesDataflowRunner = config.pythonPipelineOptions.contains("--runner=TestDataflowRunner") || config.pythonPipelineOptions.contains("--runner=DataflowRunner")
       String ver = project.findProperty('testJavaVersion')
       def javaContainerSuffix = ver ? getSupportedJavaVersion(ver) : getSupportedJavaVersion()
+      // When a specific test JDK is requested (-PtestJavaVersion), launch the Python-started
+      // expansion service on it as well (see the exec block below). Some bundled IOs (e.g.
+      // IcebergIO) are compiled for Java 17, so the expansion service must run on a JDK that can
+      // load them. Mirrors the JAVA_HOME handling in the other cross-language task factories.
+      String testJavaHome = ver ? project.findProperty("java${ver}Home") : null
 
       // Sets up, collects, and runs Python pipeline tests
       project.tasks.register(config.name+"PythonUsingJava") {
@@ -2750,6 +2755,9 @@ class BeamModulePlugin implements Plugin<Project> {
           project.exec {
             // environment variable to indicate that jars have been built
             environment "EXPANSION_JARS", config.expansionProjectPaths
+            if (testJavaHome) {
+              environment "JAVA_HOME", testJavaHome
+            }
             String additionalDependencyCmd = ""
             if (config.additionalDeps != null && !config.additionalDeps.isEmpty()){
               additionalDependencyCmd = "&& pip install ${config.additionalDeps.join(' ')} "