Can't share cloud trajectory

[blairlyons]

Description

When trying to share simulation loaded from Dropbox, I get a warning that the current file is stored on my device.

Expected Behavior

Since the file was hosted on Dropbox, it should be possible to share it.

Reproduction

1. Load https://staging.simularium.allencell.org/viewer?trajUrl=https://www.dropbox.com/scl/fi/2srfuliyjnu3sr1tlfgwf/cells_2023-10-04.simularium?rlkey=hg35vs9cwrla19eq2m0al81t4
2. Choose 'Share'
3. Unable to share, warning says 'The current file is stored on your device.'

Environment

Firefox, staging (share button is not yet released to prod)