javaunohelper: Using "final" modifier whenever applicable in java

* com.sun.star.lib.uno.adapter.ByteArrayToXInputStreamAdapter class may be final. There is a overridable method call in the constructor.

* Private methods can't be overridden. The private method "instantiate" is declared final in the com.sun.star.lib.uno.helper.Factory class.

Change-Id: I7dba78a3d1857bbc328f6a581d8e9a5ae130739d
Reviewed-on: https://gerrit.libreoffice.org/11546Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
Tested-by: Stephan Bergmann <sbergman@redhat.com>

javaunohelper/com/sun/star/lib/uno/adapter/ByteArrayToXInputStreamAdapter.java

@@ -28,7 +28,7 @@ import com.sun.star.io.XInputStream;
 import com.sun.star.io.XSeekable;
 import  com.sun.star.lib.uno.helper.ComponentBase;
 
-public class ByteArrayToXInputStreamAdapter
+public final class ByteArrayToXInputStreamAdapter
     extends ComponentBase
     implements XInputStream, XSeekable
 {

javaunohelper/com/sun/star/lib/uno/helper/Factory.java

@@ -165,7 +165,7 @@ public class Factory
     }
 
 
-    private final Object instantiate( XComponentContext xContext )
+    private Object instantiate( XComponentContext xContext )
         throws com.sun.star.uno.Exception
     {
         try