Remove 'virtual' and 'override' qualifiers on final methods.

Cpplint considers that 'virtual' and 'override' qualifers are
redundant for methods declared 'final'.

Test: mmma art
Change-Id: If4de1e1fe306f2ee3db9534930b1d24abeaf9fe4
diff --git a/compiler/utils/assembler.h b/compiler/utils/assembler.h
index 251b82c..096410d 100644
--- a/compiler/utils/assembler.h
+++ b/compiler/utils/assembler.h
@@ -292,7 +292,7 @@
   };
 
   // This method is called the by the opcode writers.
-  virtual void ImplicitlyAdvancePC() final;
+  void ImplicitlyAdvancePC() final;
 
   explicit DebugFrameOpCodeWriterForAssembler(Assembler* buffer)
       : dwarf::DebugFrameOpCodeWriter<>(false /* enabled */),