Specify --max_timestamp when calling brillo_update_payload.

Bug: 36232423
Test: Create OTA packages (full, incremental and downgrade) with
      ota_from_target_files.py; check the parameters passed down to
      brillo_update_payload.
Change-Id: I3af397f05fe16f4a9f0eb73e8272bac6afdc002a
Merged-In: I3af397f05fe16f4a9f0eb73e8272bac6afdc002a
(cherry picked from commit ed08bc4a2267c038ce4834fc65a6693a7e0223af)
(cherry picked from commit d21de1b1c3494e121149be0d1e155d0ef4bc08a5)
diff --git a/tools/releasetools/ota_from_target_files.py b/tools/releasetools/ota_from_target_files.py
index b69ddac..faf8f36 100755
--- a/tools/releasetools/ota_from_target_files.py
+++ b/tools/releasetools/ota_from_target_files.py
@@ -1212,6 +1212,11 @@
          "--target_image", target_file]
   if source_file is not None:
     cmd.extend(["--source_image", source_file])
+  if OPTIONS.downgrade:
+    max_timestamp = GetBuildProp("ro.build.date.utc", OPTIONS.source_info_dict)
+  else:
+    max_timestamp = metadata["post-timestamp"]
+  cmd.extend(["--max_timestamp", max_timestamp])
   p1 = common.Run(cmd, stdout=subprocess.PIPE)
   p1.wait()
   assert p1.returncode == 0, "brillo_update_payload generate failed"