Create a presigned upload URL for a marketplace demo image asset

Returns a presigned PUT URL for uploading an image asset into the marketplace demo’s virtual folder in the publicly-accessible bucket. The URL is time-limited (default 2 hours) and may be reused until it expires; each successful PUT overwrites the object at the signed key. The URL is signed with the declared size as Content-Length and the declared content_type as Content-Type, so the client must upload exactly that many bytes (capped at 5000000 bytes) with a matching Content-Type header, otherwise the upload will be rejected. To intentionally overwrite an already-listed filename, request a new URL with ignore_existing_image set to true (or reuse an unexpired URL for that same key, size, and content type). Additionally, there is a 200 image per demo limit. The browser may show a limit of 100 images so a resized thumbnail can be stored too. See the boto3 docs for an example of uploading with curl: https://boto3.amazonaws.com/v1/documentation/api/latest/guide/s3-presigned-urls.html

Required scope: air:marketplace_demo_write (roles: air_demo_manager, air_org_admin, air_user)

Additional permissions:

• Only members of the owning organization, Air admins, or SREs may perform this action on this marketplace demo.
• Applies whether or not the demo is published.