Merge pull request #55856 from miaoyq/replace-for-with-sets

Automatic merge from submit-queue (batch tested with PRs 53689, 56880, 55856, 59289, 60249). 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>.

Use `sets` instead of `for` statement in "IsValidAuthorizationMode"

**What this PR does / why we need it**:
Use `sets` instead of `for` statement in "IsValidAuthorizationMode", that will make the code more clearly and concisely.

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #

**Special notes for your reviewer**:

**Release note**:

```release-note
none
```

pkg/kubeapiserver/authorizer/modes/BUILD

@@ -16,6 +16,7 @@ go_library(
     name = "go_default_library",
     srcs = ["modes.go"],
     importpath = "k8s.io/kubernetes/pkg/kubeapiserver/authorizer/modes",
+    deps = ["//vendor/k8s.io/apimachinery/pkg/util/sets:go_default_library"],
 )
 
 filegroup(

pkg/kubeapiserver/authorizer/modes/modes.go

@@ -16,6 +16,8 @@ limitations under the License.
 
 package modes
 
+import "k8s.io/apimachinery/pkg/util/sets"
+
 const (
 	ModeAlwaysAllow string = "AlwaysAllow"
 	ModeAlwaysDeny  string = "AlwaysDeny"
@@ -29,10 +31,5 @@ var AuthorizationModeChoices = []string{ModeAlwaysAllow, ModeAlwaysDeny, ModeABA
 
 // IsValidAuthorizationMode returns true if the given authorization mode is a valid one for the apiserver
 func IsValidAuthorizationMode(authzMode string) bool {
-	for _, validMode := range AuthorizationModeChoices {
-		if authzMode == validMode {
-			return true
-		}
-	}
-	return false
+	return sets.NewString(AuthorizationModeChoices...).Has(authzMode)
 }