Add UpdateAttempterIntegrationTesting

Test: th
Bug: 201099341

Change-Id: I46d5ad86e238d28b7c20ef6768ffadf0e6ab9177
diff --git a/common/utils.h b/common/utils.h
index 003455d..50b6cb1 100644
--- a/common/utils.h
+++ b/common/utils.h
@@ -361,6 +361,8 @@
 
 std::unique_ptr<android::base::MappedFile> GetReadonlyZeroBlock(size_t size);
 
+std::string_view GetReadonlyZeroString(size_t size);
+
 }  // namespace utils
 
 // Utility class to close a file descriptor
@@ -481,6 +483,7 @@
 };
 
 std::string HexEncode(const brillo::Blob& blob) noexcept;
+std::string HexEncode(const std::string_view blob) noexcept;
 
 }  // namespace chromeos_update_engine