Revert "Revert "[mcp-account-manager] Delay creating accounts until enabled for the first time""

This reverts commit 0284b500bb5d64b889a4f5768bdd9d46c41735c8. The
crashes that led to this revert turned out to be coincidentally timed
and unrelated.
Merge pull request #13 from special/master

Revert "Revert "[mcp-account-manager] Delay creating accounts until enabled for the first time"