[RenderScript] Fail with Exception from validateObjectIsPrimitiveArray

Bug: http://b/25982676

Instead of returning null from validateObjectIsPrimitiveArray, fail with
an exception.  The callers of this function do not check for null.

Change-Id: Idd2b50a7b137e8d2db7a334bb9a48c1b19ee2403
1 file changed