Verify for_each is const

Test: this
Change-Id: I7ffd755b4b762f7e8608cf84b328560783162439
diff --git a/libs/hwui/canvas/OpBuffer.h b/libs/hwui/canvas/OpBuffer.h
index 398e090..98e385f 100644
--- a/libs/hwui/canvas/OpBuffer.h
+++ b/libs/hwui/canvas/OpBuffer.h
@@ -156,7 +156,7 @@
         using F_PTR = decltype(&f);
         using THUNK = void (*)(F_PTR, void*);
         static constexpr auto jump = std::array<THUNK, sizeof...(I)>{[](F_PTR fp, void* t) {
-            (*fp)(reinterpret_cast<ItemContainer<static_cast<ItemTypes>(I)>*>(t));
+            (*fp)(reinterpret_cast<const ItemContainer<static_cast<ItemTypes>(I)>*>(t));
         }...};
 
         // Do the actual iteration of each item