[java] Synchronize method to get Selenium Manager binary (fix #11620) (#11640)

Author: bonigarcia

java/src/org/openqa/selenium/manager/SeleniumManager.java

@@ -117,7 +117,7 @@ private static String runCommand(String... command) {
    * Determines the correct Selenium Manager binary to use.
    * @return the path to the Selenium Manager binary.
    */
-    private File getBinary() {
+    private synchronized File getBinary() {
         if (binary == null) {
             try {
                 Platform current = Platform.getCurrent();