Only skip CowCopy ops with same src/dst block am: 4430ea57a7

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/1610433

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: If355620a293b59794ebd27817fb6aea48038f7c8
diff --git a/payload_consumer/vabc_partition_writer.cc b/payload_consumer/vabc_partition_writer.cc
index aa8c3ce..0843fff 100644
--- a/payload_consumer/vabc_partition_writer.cc
+++ b/payload_consumer/vabc_partition_writer.cc
@@ -102,11 +102,11 @@
   std::vector<uint8_t> buffer(block_size);
 
   for (const auto& cow_op : converted) {
-    if (cow_op.src_block == cow_op.dst_block) {
-      continue;
-    }
     switch (cow_op.op) {
       case CowOperation::CowCopy:
+        if (cow_op.src_block == cow_op.dst_block) {
+          continue;
+        }
         TEST_AND_RETURN_FALSE(
             cow_writer->AddCopy(cow_op.dst_block, cow_op.src_block));
         break;