update_engine: uint64_t of partition size

On 32-bit device(mainly Android Go device), the size_t type is uint32. Overflow occurs when the total size of all partitions > 2^32 bytes, causing the partitionw_eight_.back() value to be smaller than the true size, and the progress of the FilesystemVerifierAction exceeds 100%

Change-Id: Idfb35c96c7f9cefb7fe4ebd1e369123dfac98f85
diff --git a/payload_consumer/filesystem_verifier_action.h b/payload_consumer/filesystem_verifier_action.h
index d8cb902..2adf62e 100644
--- a/payload_consumer/filesystem_verifier_action.h
+++ b/payload_consumer/filesystem_verifier_action.h
@@ -176,7 +176,7 @@
   // Cumulative sum of partition sizes. Used for progress report.
   // This vector will always start with 0, and end with total size of all
   // partitions.
-  std::vector<size_t> partition_weight_;
+  std::vector<uint64_t> partition_weight_;
 
   DISALLOW_COPY_AND_ASSIGN(FilesystemVerifierAction);
 };