Add java.specification.maintenance.version=4 jdk8 system property

As per the jdk8 JSR 337 Maintenance Release 4 spec
https://jcp.org/aboutJava/communityprocess/maintenance/jsr337/jsr337-mr4-changes.html

See also OpenJDK 8285497
ibmruntimes/openj9-openjdk-jdk8@df84c26

Signed-off-by: Peter Shipton <Peter_Shipton@ca.ibm.com>

runtime/vm/vmprops.c

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 1991, 2021 IBM Corp. and others
+ * Copyright (c) 1991, 2022 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -628,6 +628,13 @@ initializeSystemProperties(J9JavaVM * vm)
 	}
 #endif /* JAVA_SPEC_VERSION < 12 */
 
+#if JAVA_SPEC_VERSION == 8
+	rc = addSystemProperty(vm, "java.specification.maintenance.version", "4", 0);
+	if (J9SYSPROP_ERROR_NONE != rc) {
+		goto fail;
+	}
+#endif /* JAVA_SPEC_VERSION == 8 */
+
 	rc = addSystemProperty(vm, "java.vm.vendor", JAVA_VM_VENDOR, 0);
 	if (J9SYSPROP_ERROR_NONE != rc) {
 		goto fail;