We still panic in a debug build, so that developers can notice when they
need to add a new static atom after modifying UA sheets.
We also add telemetry to note when this happens, add an app note to a
crash report, in case any crash later on occurs, and re-up the existing,
expired shared memory sheet telemetry probes so we can look at them
again.
Differential Revision: https://phabricator.services.mozilla.com/D73188
