Handle failure cases on startup gracefully to avoid causing cascading
errors and poor initialization in other components. Initial errors from
config load cause the initializer to pause and hold requests. Return
typed errors to better communicate failures to clients.
Add code to handle two specific cases - admin wants to bypass
initialization defaulting, and mirror pods (which want to bypass
initialization because the kubelet owns their lifecycle).
Automatic merge from submit-queue (batch tested with PRs 45346, 45903, 45958, 46042, 45975)
ResourceQuota admission control injects registry
**What this PR does / why we need it**:
The `ResourceQuota` admission controller works with a registry that maps a GroupKind to an Evaluator. The registry used in the existing plug-in is not injectable, which makes usage of the ResourceQuota plug-in in other API server contexts difficult. This PR updates the code to support late injection of the registry via a plug-in initializer.
this is a two stage refactor when done there will be no init block in admission plugins.
Instead all plugins expose Register function which accept admission.Plugins instance.
The registration to global plugin registry happens inside Register func.
