clean up and add javadocs

Change-Id: I7f628106247de887cd91c4a4b4b55d3ebfa700c8
diff --git a/graphics/java/android/renderscript/FieldPacker.java b/graphics/java/android/renderscript/FieldPacker.java
index 40628bc..bdda830 100644
--- a/graphics/java/android/renderscript/FieldPacker.java
+++ b/graphics/java/android/renderscript/FieldPacker.java
@@ -18,8 +18,8 @@
 
 
 /**
- * Utility class for packing arguments and structures from java objects to rs
- * objects.
+ * Utility class for packing arguments and structures from Android system objects to
+ * Renderscript objects.
  *
  **/
 public class FieldPacker {