Use swh.model.hashutil.MultiHash in swh.indexer.tests.test_utils.fill_storage
Currently, swh.indexer.tests.test_utils.fill_storage
computes hashes itself (some are even dummy values). swh.model.hashutil.MultiHash
should be used instead, that's what it's for.
Migrated from T1448 (view on Phabricator)