Merge pull request #65298 from nikhita/cherrypick-jsoniter-bump-1.9

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

vendor/github.com/json-iterator/go/README.md

@@ -8,6 +8,8 @@
 
 A high-performance 100% compatible drop-in replacement of "encoding/json"
 
+You can also use thrift like JSON using [thrift-iterator](https://github.com/thrift-iterator/go)
+
 ```
 Go开发者们请加入我们，滴滴出行平台技术部 taowen@didichuxing.com
 ```
@@ -29,6 +31,9 @@ Raw Result (easyjson requires static code generation)
 | easyjson encode | 883 ns/op | 576 B/op | 3 allocs/op |
 | jsoniter encode | 837 ns/op | 384 B/op | 4 allocs/op |
 
+Always benchmark with your own workload. 
+The result depends heavily on the data input.
+
 # Usage
 
 100% compatibility with standard lib
@@ -44,7 +49,9 @@ with
 
 ```go
 import "github.com/json-iterator/go"
-jsoniter.Marshal(&data)
+
+var json = jsoniter.ConfigCompatibleWithStandardLibrary
+json.Marshal(&data)
 ```
 
 Replace
@@ -58,7 +65,9 @@ with
 
 ```go
 import "github.com/json-iterator/go"
-jsoniter.Unmarshal(input, &data)
+
+var json = jsoniter.ConfigCompatibleWithStandardLibrary
+json.Unmarshal(input, &data)
 ```
 
 [More documentation](http://jsoniter.com/migrate-from-go-std.html)
@@ -76,5 +85,7 @@ Contributors
 * [thockin](https://github.com/thockin) 
 * [mattn](https://github.com/mattn)
 * [cch123](https://github.com/cch123)
+* [Oleg Shaldybin](https://github.com/olegshaldybin)
+* [Jason Toffaletti](https://github.com/toffaletti)
 
 Report issue or pull request, or email taowen@gmail.com, or [![Gitter chat](https://badges.gitter.im/gitterHQ/gitter.png)](https://gitter.im/json-iterator/Lobby)