Various counters would expose either project names, or full project
paths (e.g. "gitlab-org/gitlab-ce"). This commit changes various places
where we use "add_event" so we no longer expose (potentially) private
information.
Fixes that make this work:
* A change in Ruby (ce635262f5)
requires passing in the exact required length for OpenSSL keys and IVs.
* Ensure the secrets.yml is generated before any prepended modules are
loaded. This is done by renaming the `secret_token.rb` initializer to
`01_secret_token.rb`, which is a bit ugly but involves the least impact on
other files.
