We have found that on slower machine, the creation of the admin.system.keys collection when enabling the key generator (which generates an oplog entry and therefore ticking the cluster time) can occur before the node has finished gossiping out the updated cluster time. 

Currently, we enable the key generator during both mongod and config server tests. However, since enabling the key generator is necessary to write new keys to the config server primary, we can safely remove the function call from the mongod tests. 

To avoid a race condition on the cluster time when enabling the key generator in the config server tests in environments with slower machines, we need to ensure that the corresponding admin.system.keys collection is created before invoking enableKeyGenerator.