When the webhook lease in the knative-serving namespace is left in inconsistent state (with holderIdentity set, perhaps due to unclean webhook crash or uninstallation)

Installing KnativeServing fails with the webhook in a CrashLoopBackOff state indefinitely, as the liveness probe kills the webhook before it has time to acquire the lease.

To reproduce:
1. Create KnativeServing
2. Delete KnativeServing
3. Fake lease inconsistency

oc patch lease -n knative-serving webhook.webhookcertificates.00-of-01 -p '{"spec":{"holderIdentity":"foobar"}}'

4. Create KnativeServing
5. Notice the webhook crashloops, as its killed by liveness before it can acquire the lease

Adding some initialDelaySeconds to the webhook liveness probe seems to fix the problem