Changes to Submit a new image for analysis by the engine

added the new optional request property source/import

the request property source/archive became nullable

the request property source/digest became nullable

the request property source/tag became nullable

the request property source/digest/creation_timestamp_override became optional

the request property source/archive became not nullable

the request property source/digest became not nullable

the request property source/tag became not nullable

the request property source/digest/creation_timestamp_override became required

removed the request property source/import