There are a few AIs in terms of ensuring we don't ship a build without signing/symbols being available:
https://docs.google.com/document/d/1m19hRSU7FFc0UfrbHLQBJx0onAbDWZx8ezRjx0fZFfo/edit

1) Update docs/processes so no release if signing failures.
2) Need to ensure no builds are available if jobs fail. 
3) Update testing plan so we check for symbols during validation.