KeepGoing tweaks

After talking to Kenan there are a few issues that stop this getting
signed off - this addresses those
* Avoid race conditions with mw.loader.using - prefetch still but wrap
the creation of KeepGoingOverlay in another mw.loader.using in case the
first one failed
* KeepGoing should still run even if in 'random' campaign or other
campaign

Change-Id: I3ee2b098d8da6eb869d8238fc0f8a0a1c5f698eb
Merge "KeepGoing tweaks"