Mark model fields final

Summary: These are already considered immutable, but not marked in their class.

Reviewed By: emilsjolander

Differential Revision: D6759564

fbshipit-source-id: 810dc8a9730fb330760d2aedecafcea81cf25cb1

java/com/facebook/yoga/YogaAlign.java

@@ -22,7 +22,7 @@ public enum YogaAlign {
   SPACE_BETWEEN(6),
   SPACE_AROUND(7);
 
-  private int mIntValue;
+  private final int mIntValue;
 
   YogaAlign(int intValue) {
     mIntValue = intValue;