Add support for validating image downloads using secure hash algorithms (SHA256, SHA512, etc.) via the ``os_hash_algo`` and ``os_hash_value`` metadata fields. This addresses the limitation of MD5-only validation and improves data integrity verification. Closes-Bug: #2130662 Change-Id: I16c0c949c2382274daaf9fd6dad3f0ecad353b9c Signed-off-by: Afonne-CID <afonnepaulc@gmail.com>