ready. Until this is called the asset stays pending and is excluded from media
listings.
Signature
ConfirmOptions
Returns
The stored*dreep.MediaAsset. The call is
idempotent: an asset that is already ready is returned as-is. If the API answers with an
empty body, the asset and the error are both nil.
Transforming on confirm
Errors
IsConflict means the PUT hasn’t landed — retry the confirm, not the upload.
UploadPresigned does
this for you.