Allow UpdateAttempterAndroid to override otacerts path

For unittest to override otacerts on device, provide a small interface

Test: th
Change-Id: I9e156cbf7135f1afd13a9a7aa23a5245898023e5
diff --git a/aosp/update_attempter_android.h b/aosp/update_attempter_android.h
index 7fa01e8..5d832e0 100644
--- a/aosp/update_attempter_android.h
+++ b/aosp/update_attempter_android.h
@@ -133,6 +133,11 @@
   // 3. When user called |ResetStatus()|
   bool ClearUpdateCompletedMarker();
 
+  void set_update_certificates_path(
+      const std::string& update_certificates_path) {
+    update_certificates_path_ = update_certificates_path;
+  }
+
  private:
   friend class UpdateAttempterAndroidTest;
 
@@ -274,6 +279,9 @@
   // CleanupPreviousUpdateAction has not been executed.
   std::optional<ErrorCode> cleanup_previous_update_code_{std::nullopt};
 
+  // The path to the zip file with X509 certificates.
+  std::string update_certificates_path_{constants::kUpdateCertificatesPath};
+
   DISALLOW_COPY_AND_ASSIGN(UpdateAttempterAndroid);
 };