git_url (and others) are bad fields on collection content

[mdellweg]

          I think this assertion fails due to the parallel nature of the test. In other parallel sync tests we sync the amazon.aws collection which means the git sync will use that version already present in the system (name,namespace uniqeuness strikes again) causing the metadata to differ.

Originally posted by @gerrod3 in #1711 (comment)

[mdellweg]

We need to remove them.
In general, as long as we allow content to be shared, the content itself cannot tell you where it came from.

[newswangerd]

as long as we're not removing any fields that come from metadata/manifest, this should be fine.

We definitely need to keep fields such as metadata["repository'].

[mdellweg]

as long as we're not removing any fields that come from metadata/manifest, this should be fine.

We definitely need to keep fields such as metadata["repository'].

That metadata is part of the actual collection artifact, right? Then there's no issue with that.