rename method from 'Clone' to 'clone' in 'Engine' class to match the java naming convention and definiont in the of java.lang.Object. (#268)

Co-authored-by: Cristi Balcanu <balcanu@amazon.com>

bindings/java/src/main/java/com/microsoft/regorus/Engine.java

@@ -60,7 +60,7 @@ public class Engine implements AutoCloseable, Cloneable {
     /**
      * Efficiently clones an Engine.
      */
-    public Engine Clone() {
+    public Engine clone() {
 	return new Engine(nativeClone(enginePtr));
     }