When restarting a two-phase index build, we should check if the node had already voted to commit the index and log a warning message, so that the situation can be easily observed and monitored.  Since a vote to commit, once issued, cannot currently be "retracted" by a node, if node has to restart the index build once it had already voted, it could lead to a situation in which the primary commits the index build, leaving a window of time where the restarted node needs to catch up before it can apply further oplog entries; in these cases, easy observability can help diagnose issues more rapidly.

The state can be observed by looking at the config database's system.indexBuilds collection, and should be emitted whenever an index build restart needs to occur when the node is already in the list of commitReadyMembers.