More convenient means of resolving publish flakes

[jeremyk-91]

Currently if publish flakes with some artifacts being published, it's rather annoying:

1. Releasing the same commit has been done in the past, but this seems a bit shady and isn't allowed by autorelease-bot (reasonably)
2. Retriggering the build often doesn't work, because the way we do bintray uploads is not atomic

Probably want the buildscript to be resilient in some way to the 409s we might get (possibly --continue in gradle), or see if there's a way to hit bintray atomically