The reconcile loop sets `DeploymentState.DesiredCanaries` only on the first
pass through the loop and if the job is not paused/pending. In MRD,
deployments will make one pass though the loop while "pending", and were not
ever getting `DesiredCanaries` set. We can't set it in the initial
`DeploymentState` constructor because the first pass through setting up
canaries expects it's not there yet. However, this value is static for a given
version of a job because it's coming from the update stanza, so it's safe to
re-assign the value on subsequent passes.
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