Automatic merge from submit-queue (batch tested with PRs 40215, 40340, 39523)

Retry resource quota lookup until count stabilizes

On contended servers the service account controller can slow down,
leading to the count changing during a run. Wait up to 5s for the count
to stabilize, assuming that updates come at a consistent rate, and are
not held indefinitely.

Upstream of openshift/origin#12605 (we create more secrets and flake more often)