Dont strip class names referenced from native

Summary: Ensure we don't strip classes used from native

Reviewed By: lexs

Differential Revision: D4237790

fbshipit-source-id: 1bd0780d965efbb8334917011ffd65896670ece1

java/com/facebook/csslayout/CSSJustify.java

@@ -9,6 +9,9 @@
 
 package com.facebook.csslayout;
 
+import com.facebook.proguard.annotations.DoNotStrip;
+
+@DoNotStrip
 public enum CSSJustify {
   FLEX_START(0),
   CENTER(1),