Fix File pathSeparator literal in StampedLock test

Author: shai-almog

vm/tests/src/test/java/com/codename1/tools/translator/StampedLockIntegrationTest.java

@@ -262,7 +262,7 @@ private void writeMockJavaClasses(Path sourceDir) throws Exception {
                 "public class File {\n" +
                 "    public static final String separator = \"/\";\n" +
                 "    public static final char separatorChar = '/';\n" +
-                "    public static final String pathSeparator = \":";\n" +
+                "    public static final String pathSeparator = \":\";\n" +
                 "    public static final char pathSeparatorChar = ':';\n" +
                 "    private String path;\n" +
                 "    public File(String pathname) { this.path = pathname == null ? \"\" : pathname; }\n" +