Add some more DISALLOW_COPY_AND_ASSIGN

May help prevent bugs maybe.

Change-Id: Ie73d469dfcd078492ecb3aa28682b42707221202
diff --git a/runtime/gc/accounting/card_table.h b/runtime/gc/accounting/card_table.h
index 75ef58a..34e6aa3 100644
--- a/runtime/gc/accounting/card_table.h
+++ b/runtime/gc/accounting/card_table.h
@@ -146,6 +146,8 @@
   // Card table doesn't begin at the beginning of the mem_map_, instead it is displaced by offset
   // to allow the byte value of biased_begin_ to equal GC_CARD_DIRTY
   const size_t offset_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(CardTable);
 };
 
 }  // namespace accounting