Fix BazelTestRunner compatibility with jre8

Removes usages of Set.of() that were introduced in javase9

Fixes #18300

Closes #18307.

PiperOrigin-RevId: 529369593
Change-Id: Id45afbb1bdee46910f4a9b632f479773c561c0a3

Author: hvadehra

src/java_tools/junitrunner/java/com/google/testing/junit/runner/junit4/JUnit4Bazel.java

@@ -23,6 +23,7 @@
 import com.google.testing.junit.runner.sharding.ShardingFilters;
 import com.google.testing.junit.runner.util.MemoizingSupplier;
 import java.io.PrintStream;
+import java.util.Collections;
 import java.util.Set;
 import java.util.function.Supplier;
 import org.junit.runner.Request;
@@ -83,7 +84,7 @@ public JUnit4Runner runner() {
         stdoutStream,
         config,
         setOfRunListeners,
-        Set.of());
+        Collections.emptySet());
   }
 
   /** A builder for instantiating {@link JUnit4Bazel}. */

src/java_tools/junitrunner/java/com/google/testing/junit/runner/junit4/JUnit4RunnerModule.java

@@ -31,6 +31,8 @@
 import java.io.OutputStream;
 import java.io.PrintStream;
 import java.nio.file.Path;
+import java.util.Collections;
+import java.util.HashSet;
 import java.util.Set;
 import java.util.function.Supplier;
 import javax.annotation.Nullable;
@@ -127,17 +129,20 @@ Set<RunListener> setOfRunListeners(
       JUnit4Config config,
       Supplier<TestSuiteModel> testSuiteModelSupplier,
       CancellableRequestFactory cancellableRequestFactory) {
-    return Set.of(
+    Set<RunListener> listeners = new HashSet<>();
+    listeners.add(
         new JUnit4TestStackTraceListener(
-            new SignalHandlers(SignalHandlers.createRealHandlerInstaller()), System.err),
+            new SignalHandlers(SignalHandlers.createRealHandlerInstaller()), System.err));
+    listeners.add(
         new JUnit4TestXmlListener(
             testSuiteModelSupplier,
             cancellableRequestFactory,
             new SignalHandlers(SignalHandlers.createRealHandlerInstaller()),
             new ProvideXmlStreamFactory(() -> config).get(),
-            System.err),
-        new JUnit4TestNameListener(provideCurrentRunningTest()),
-        JUnit4RunnerBaseModule.provideTextListener(stdout()));
+            System.err));
+    listeners.add(new JUnit4TestNameListener(provideCurrentRunningTest()));
+    listeners.add(JUnit4RunnerBaseModule.provideTextListener(stdout()));
+    return Collections.unmodifiableSet(listeners);
   }
 
   CancellableRequestFactory cancellableRequestFactory() {