Merge pull request #39152 from liggitt/json-tags

Automatic merge from submit-queue (batch tested with PRs 39152, 39142, 39055)

Add test for json tags on internal and external types

Follow up from https://github.com/kubernetes/kubernetes/pull/38406

- adds static analysis tests preventing internal types from adding new json or protobuf tags
- adds static analysis tests requiring json tags on external types (and enforcing lower-case first letter)
- fixes issues found by the tests

pkg/api/types.go

@@ -1933,7 +1933,7 @@ type PodStatus struct {
 	// +optional
 	StartTime *metav1.Time
 	// +optional
-	QOSClass PodQOSClass `json:"qosClass,omitempty"`
+	QOSClass PodQOSClass
 
 	// The list has one entry per init container in the manifest. The most recent successful
 	// init container will have ready = true, the most recently started container will have