We weren't able to test the betatest channel due to this. http://kb.mozillazine.org/Software_update says about:config doesn't work (it doesn't). A way to change channels so we can test updates before pushing an update live will become very important once we're live.
QA normally changes <app>/defaults/pref/channel-prefs.js prior to starting the app. Is that available on Android ?
Fennec puts the app.update.channel in the <app>/defaults/preferences/mobile.js file, but on Android everything is bundled in the omnijar, so it's harder to extract-edit-repackage. I noticed in the code that we could play a trick using the partner update channel: http://mxr.mozilla.org/mozilla-central/source/toolkit/mozapps/update/nsUpdateService.js#586 That is the code that gets the channel used in the AUS URL. The preference is read from the default branch, so even if you try to override "app.update.channel" in about:config, it won't work. However, notice how we look for partner channel info too? We might be able to tweak the channel using about:config. Something like: "app.partner.test" = "test" would create a channel like: "beta-cck-test"
Pushing to beta-cck-test and using app.partner.test = test worked. We probably want to doc this for testers; I've got it in my build notes and probably want to automate it. But we definitely have a way to switch update channels.
Verified: Mozille/5.0 (Android; Linux armv71; rv:2.0b7pre) Gecko20101006 Firefox/4.0b7pre Fennec/4.0b1
[13:38] <nthomas> the other option is to copy app.update.url to app.update.url.override and s/%CHANNEL%/betatest/