Automatic merge from submit-queue.
Manual cherrypick of #65034 to 1.9: make json serializer case sensitive
fixes partially https://github.com/kubernetes/kubernetes/issues/64612
This PR imports the latest jsoniterator library so that case sensitivity during unmarshalling is optional. The PR also sets Kubernetes json serializer to be case sensitive.
**Release note**:
```release-note
ACTION REQUIRED: Kubernetes JSON deserializer is now case-sensitive to restore compatibility with pre-1.8 servers. If your config files contains fields with wrong case, the config files will be now invalid.
```
/sig api-machinery
/kind bug
/assign caesarxuchao liggitt thockin sttts mbohlool
Kubernetes-commit: f4cf484c2cb6056e28fb9759a3c913be3eed990a
