The fields to update on the entry. If absent or empty, all
modifiable fields are updated. The following fields are
modifiable: * For entries with type DATA_STREAM: *
schema * For entries with type FILESET * schema
* display_name * description * gcs_fileset_spec
* gcs_fileset_spec.file_patterns * For entries with
user_specified_type * schema * display_name *
description * user_specified_type *
user_specified_system * linked_resource *
source_system_timestamps