java: move -version handling to RunJava

It does not belong in the isolate API but to the
command line java starter.

java/runjava/src/main/java/io/osv/ContextIsolator.java

@@ -128,16 +128,6 @@ public class ContextIsolator {
                 String key = args[i].substring(2, eq);
                 String value = args[i].substring(eq + 1, args[i].length());
                 System.setProperty(key, value);
-            } else if (args[i].equals("-version")) {
-                System.err.println("java version \"" +
-                        System.getProperty("java.version") + "\"");
-                System.err.println(System.getProperty("java.runtime.name") +
-                        " (" + System.getProperty("java.runtime.version") +
-                        ")");
-                System.err.println(System.getProperty("java.vm.name") +
-                        " (build " + System.getProperty("java.vm.version") +
-                        ", " + System.getProperty("java.vm.info") + ")");
-                return null;
             } else if (args[i].equals("-Xclassloader")) {
                 // Non-standard try - use a different class loader.
                 if (i + 1 >= args.length) {

java/runjava/src/main/java/io/osv/RunJava.java

@@ -10,6 +10,18 @@ package io.osv;
 public class RunJava {
 
     public static void main(String[] args) {
+        if (args[0].equals("-version")) {
+            System.err.println("java version \"" +
+                    System.getProperty("java.version") + "\"");
+            System.err.println(System.getProperty("java.runtime.name") +
+                    " (" + System.getProperty("java.runtime.version") +
+                    ")");
+            System.err.println(System.getProperty("java.vm.name") +
+                    " (build " + System.getProperty("java.vm.version") +
+                    ", " + System.getProperty("java.vm.info") + ")");
+            return;
+        }
+
         try {
             ContextIsolator.getInstance().runSync(args);
         } catch (Throwable ex) {