Comment 2 for bug 1482251

Correct, this is being set by indicator-transfer as per <https://docs.google.com/document/d/1810KDpFl2Mxsn1z3wehPU9pkbS6R6o-j1-pmYpkYb7A/edit#heading=h.cy7f9hh9fpgr> but we should probably update this to something more generic now that the indicator is being used to show more than just file downloads.