Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Add missing error handling in schema-related code
**What this PR does / why we need it**:
Adds missing error handling to a few places.
**Which issue(s) this PR fixes**
Updates #51457. Still more work to do to fix the issue - client generation code needs to be updated (addressed in https://github.com/kubernetes/kubernetes/pull/64664).
**Release note**:
```release-note
NONE
```
/kind bug
/sig api-machinery
Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Make kubernetes json serializer case sensitive
This PR imported the latest jsoniterator library so that case sensitivity during unmarhsaling is optional. The PR also set Kubernetes json serializer to be case sensitive.
Kubernetes json serializer had been case sensitive for 1.1-1.7 as we were using ugorji. This PR restores the behavior.
Fix#64612.
```release-notes
Kubernetes json deserializer is now case-sensitive as it was before 1.8.
If your config files contains fields with wrong case, the config files will be now invalid.
```
Automatic merge from submit-queue (batch tested with PRs 64127, 63895, 64066, 64215, 64202). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
kubeadm: Refactor the .Etcd substruct in the v1alpha2 API
**What this PR does / why we need it**:
Splits the monolithic `.Etcd` struct with all the options as fields to a more modular and clear design with two sub-structs for the different modes of hosting etcd we support.
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Part of kubernetes/community#2131
**Special notes for your reviewer**:
Depends on:
- [x] https://github.com/kubernetes/kubernetes/pull/63917
Follows up: https://github.com/kubernetes/kubernetes/pull/63871
TODO: I still need to write unit tests for this.
**Release note**:
```release-note
[action required] kubeadm: The `:Etcd` struct has been refactored in the v1alpha2 API. All the options now reside under either `.Etcd.Local` or `.Etcd.External`. Automatic conversions from the v1alpha1 API are supported.
```
@kubernetes/sig-cluster-lifecycle-pr-reviews @liztio
Automatic merge from submit-queue (batch tested with PRs 63151, 63795, 63553, 64068, 64113). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
kubeadm: Remove .AuthorizationModes in the v1alpha2 API
**What this PR does / why we need it**:
Now that we have https://github.com/kubernetes/kubernetes/pull/63879, we don't actually need to have `:AuthorizationModes` in our API anymore. This PR removes support for `.AuthorizationModes` in the v1alpha2 API, but keeps an upgrade path available (automatic conversion) from the v1alpha1 version.
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Part of kubernetes/community#2131
**Special notes for your reviewer**:
Depends on:
- [x] https://github.com/kubernetes/kubernetes/pull/63879
- [x] https://github.com/kubernetes/kubernetes/pull/63917
**Release note**:
```release-note
[action required] kubeadm: Support for `.AuthorizationModes` in the kubeadm v1alpha2 API has been removed. Instead, you can use the `.APIServerExtraArgs` and `.APIServerExtraVolumes` fields to achieve the same effect. Files using the v1alpha1 API and setting this field will be automatically upgraded to this v1alpha2 API and the information will be preserved.
```
@kubernetes/sig-cluster-lifecycle-pr-reviews @liztio
