Consider adding MOZ_SERVICES_HEALTHREPORT to mozconfig

Someone suggested on the blog that we unset MOZ_SERVICES_HEALTHREPORT in mozconfig: https://blog.torproject.org/comment/285469#comment-285469

Apparently unsetting this would avoid including the file toolkit/components/telemetry/healthreport-prefs.js, which currently contains:

pref("datareporting.healthreport.infoURL", "https://www.mozilla.org/legal/privacy/firefox.html#health-report");
pref("datareporting.healthreport.uploadEnabled", true);

We already set datareporting.healthreport.uploadEnabled to false, so this wouldn't fix any issue, but would be defense in depth.

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information