brillo_update_payload: Parse minor version from the metadata.

META/update_engine_config.txt contains KEY=value config options with
the supported version. This patch uses the supported minor version from
the source image to generate the right delta payload.

TEST=brillo_update_payload with old/new taget_files including and not including the update_engine_config.txt file.

Change-Id: I3dacaeeeda9bbde3991a95fbf7834542af0b5780
Commit-Ready: Alex Deymo <>
Tested-by: Alex Deymo <>
Reviewed-by: Jason Kusuma <>
Reviewed-by: Mike Frysinger <>
1 file changed