Continue error check improvements and write some docs.

Change-Id: I345b08490da21d9ee715ff1ddc80c1a816b579f4
diff --git a/graphics/java/android/renderscript/ScriptC.java b/graphics/java/android/renderscript/ScriptC.java
index 5215795..44fc5fd 100644
--- a/graphics/java/android/renderscript/ScriptC.java
+++ b/graphics/java/android/renderscript/ScriptC.java
@@ -39,7 +39,8 @@
 
     protected ScriptC(RenderScript rs, Resources resources, int resourceID) {
         super(0, rs);
-        mID = internalCreate(rs, resources, resourceID);
+        int id = internalCreate(rs, resources, resourceID);
+        setID(id);
     }