Add EmitSequenceData stub to FakeCowWriter am: fba6ee5bbb

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/1753109

Change-Id: I29278dfb92cbd9fdaa3c07b0e7124be5670d377e
diff --git a/payload_consumer/snapshot_extent_writer_unittest.cc b/payload_consumer/snapshot_extent_writer_unittest.cc
index 2201043..51672ca 100644
--- a/payload_consumer/snapshot_extent_writer_unittest.cc
+++ b/payload_consumer/snapshot_extent_writer_unittest.cc
@@ -70,6 +70,10 @@
     return true;
   }
 
+  bool EmitSequenceData(size_t num_ops, const uint32_t* data) override {
+    return false;
+  }
+
   // Return number of bytes the cow image occupies on disk.
   uint64_t GetCowSize() override {
     return std::accumulate(