Only skip operation on snapshot partitions

On Virtual A/B devices, don't skip SOURCE_COPY on
static partitions.

Test: update_engine_unittest
Test: incremental update to self
Change-Id: I5c93b501e09f50f559151eb77d83052373c90d0d
diff --git a/common/dynamic_partition_control_stub.h b/common/dynamic_partition_control_stub.h
index c62758b..1704f05 100644
--- a/common/dynamic_partition_control_stub.h
+++ b/common/dynamic_partition_control_stub.h
@@ -29,7 +29,8 @@
  public:
   FeatureFlag GetDynamicPartitionsFeatureFlag() override;
   FeatureFlag GetVirtualAbFeatureFlag() override;
-  bool ShouldSkipOperation(const InstallOperation& operation) override;
+  bool ShouldSkipOperation(const std::string& partition_name,
+                           const InstallOperation& operation) override;
   void Cleanup() override;
   bool PreparePartitionsForUpdate(uint32_t source_slot,
                                   uint32_t target_slot,