No longer recording datastore telemetry events `updated` and `deleted`

[irrationalagent]

https://sql.telemetry.mozilla.org/queries/49016/source#table

Starting last thu (2018-03-08, same day as 0.1.8 release) we stopped receiving events with category == 'lockboxv1', method == 'updated' and object == 'datastore'. We are still receiving added datastore events.

A local test on my machine confirms it is not recording (running in guest mode):

1. We are still getting the front-end (object == 'manage') events itemUpdated, itemUpdating, and itemDeleting (we never implemented an itemDeleted)

2. We are also still getting the datastore event added, so it doesn't seem to be a general issue with datastore events.

after looking at the console log, I'm seeing

Invalid extra key for event ["lockboxv1", "itemSelected", "manage"]. (unknown)
Invalid extra key for event ["lockboxv1", "deleted", "datastore"]. (unknown)

so it appears that itemSelected is also affected, and that we are trying to set the extra field incorrectly. I signed in to make sure that the fxa_uid was getting added to extra for the events that are firing and it was.

Looking at bootstrap.js, itemid was missing from the registration of itemSelected; although in src/webextension/list/popup/telemetry.js it looks as if the item id is passed to the extra field when the event is recorded. I figured this was the problem, but when I added itemid to the extras field in bootstrap.js I still got Invalid extra key for event ["lockboxv1", "itemSelected", "doorhanger"].

I also tried removing support for fields in the extra keys for the datastore events (also by modifying src/webextension/background/datastore.js ) but that didn't seem to solve the problem either.

tl;dr I think something is going wrong when adding the itemid to the extra field for some events, but I'm not sure yet.

[irrationalagent]

also getting
Invalid extra key for event ["lockboxv1", "passwordCopied", "doorhanger"].
Invalid extra key for event ["lockboxv1", "usernameCopied", "doorhanger"]

so those events seem to be affected as well

[devinreams]

I'll move this to "to do" since it's important to fix what's now seemingly broken.

Thanks for the detailed report @irrationalagent.

[jimporter]

Would a regression range help here? It sounds like the problem is something that recently changed, but it's hard to tell since our tests for telemetry are sadly incomplete.