Whether paste is enabled isn't updated often enough

[lukechurch]

Select a folder
Copy
Paste
Right click on folder, select 'copy as file path'
Right click ---

Paste is still available even though clipboard contains a file path.

However if somewhere else, other than the current folder is selected, it behaves correctly, so it seems to just be a time of refresh issue on the UI

[clayberg]

Set owner to @jwren.

[danrubel]

Removed this from the M3 milestone.
Added this to the Later milestone.

[jwren]

Added AssumedStale label.

[clayberg]

Removed this from the Later milestone.
Added this to the 1.2 milestone.