As a part of SERVER-48416, we started tracking what phase of index build a node is in. We should separate out initializing the index build and the collection scan when tracking the phase. SERVER-48476 will add a wait before doing the collection scan for an index build, but during startup we currently don't have a way to know if that wait was completed successfully or not.

Without differentiating whether the index build was before or after the wait during shutdown, startup recovery will proceed without trying to wait, which means that it may not be safe to resume the index build if the node later goes into rollback.