Counts one Pigeon upload attempt and its outcome: the session and the upload
started, then succeeded (with the purge of the delivered batch from the
store and one event.uploaded per event) or failed (the app's
sys_upload_session_failed / sys_upload_failed pair).
Counts one Pigeon upload attempt and its outcome: the session and the upload started, then succeeded (with the purge of the delivered batch from the store and one
event.uploadedper event) or failed (the app'ssys_upload_session_failed/sys_upload_failedpair).