pr 172 breaks training-operator

[zw0610]

#172 breaks training-operator when installing crd

reproduce steps:

1. change go.mod and go.sum

diff --git a/go.mod b/go.mod
index 58f089d7..d491f115 100644
--- a/go.mod
+++ b/go.mod
@@ -5,7 +5,7 @@ go 1.17
 require (
        github.com/go-logr/logr v0.3.0
        github.com/go-openapi/spec v0.20.3
-       github.com/kubeflow/common v0.3.7
+       github.com/kubeflow/common v0.4.1-0.20211106174700-a1f26a9cd2f5
        github.com/onsi/ginkgo v1.14.1
        github.com/onsi/gomega v1.10.2
        github.com/prometheus/client_golang v1.10.0

2. run make manifets

On branch master
Your branch is behind 'origin/master' by 1 commit, and can be fast-forwarded.
  (use "git pull" to update your local branch)

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
	modified:   go.mod
	modified:   go.sum
	modified:   manifests/base/crds/kubeflow.org_mxjobs.yaml
	modified:   manifests/base/crds/kubeflow.org_pytorchjobs.yaml
	modified:   manifests/base/crds/kubeflow.org_tfjobs.yaml
	modified:   manifests/base/crds/kubeflow.org_xgboostjobs.yaml

no changes added to commit (use "git add" and/or "git commit -a")

3. run make install

which: no golangci-lint in (/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin:/usr/local/go/bin)
/root/test/training-operator/bin/controller-gen "crd:trivialVersions=true,preserveUnknownFields=false,generateEmbeddedObjectMeta=true" rbac:roleName=manager-role webhook paths="./pkg/apis/..." output:crd:artifacts:config=manifests/base/crds
go: creating new go.mod: module tmp
Downloading sigs.k8s.io/kustomize/kustomize/[email protected]
go: downloading sigs.k8s.io/kustomize/kustomize/v3 v3.8.7
...
go get: added sigs.k8s.io/yaml v1.2.0
/root/test/training-operator/bin/kustomize build manifests/base/crds | kubectl apply -f -
Error from server (Invalid): error when creating "STDIN": CustomResourceDefinition.apiextensions.k8s.io "mxjobs.kubeflow.org" is invalid: spec.validation.openAPIV3Schema.properties[status].properties[conditions].items.x-kubernetes-map-type: Invalid value: "null": must be atomic as item of a list with x-kubernetes-list-type=set
Error from server (Invalid): error when creating "STDIN": CustomResourceDefinition.apiextensions.k8s.io "pytorchjobs.kubeflow.org" is invalid: spec.validation.openAPIV3Schema.properties[status].properties[conditions].items.x-kubernetes-map-type: Invalid value: "null": must be atomic as item of a list with x-kubernetes-list-type=set
Error from server (Invalid): error when creating "STDIN": CustomResourceDefinition.apiextensions.k8s.io "tfjobs.kubeflow.org" is invalid: spec.validation.openAPIV3Schema.properties[status].properties[conditions].items.x-kubernetes-map-type: Invalid value: "null": must be atomic as item of a list with x-kubernetes-list-type=set
Error from server (Invalid): error when creating "STDIN": CustomResourceDefinition.apiextensions.k8s.io "xgboostjobs.kubeflow.org" is invalid: spec.validation.openAPIV3Schema.properties[status].properties[conditions].items.x-kubernetes-map-type: Invalid value: "null": must be atomic as item of a list with x-kubernetes-list-type=set
make: *** [Makefile:83: install] Error 1