Skip registering "crd-remap-version" plugin when feature flag (#5165)

"EnableAPIGroupVersions" is set

The crd-remap-version plugin will always backup v1b1 resource for some
CRD. It impacts the feature flag `EnableAPIGroupVersions` which means to
backup all versions, and make migration fail.

In this commit the featureSet was removed from plugin server struct b/c
it blocks the parm `--features` to be populated correctly.  This change
should not have negative impact b/c the attribute in server struct is never used.

Fixes #5146

Signed-off-by: Daniel Jiang <jiangd@vmware.com>

pkg/plugin/framework/server.go

@@ -25,7 +25,6 @@ import (
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/pflag"
 
-	veleroflag "github.com/vmware-tanzu/velero/pkg/cmd/util/flag"
 	"github.com/vmware-tanzu/velero/pkg/util/logging"
 )
 
@@ -78,6 +77,7 @@ type Server interface {
 
 	// RegisterItemSnapshotters registers multiple Item Snapshotters
 	RegisterItemSnapshotters(map[string]HandlerInitializer) Server
+
 	// Server runs the plugin server.
 	Serve()
 }
@@ -87,7 +87,6 @@ type server struct {
 	log               *logrus.Logger
 	logLevelFlag      *logging.LevelFlag
 	flagSet           *pflag.FlagSet
-	featureSet        *veleroflag.StringArray
 	backupItemAction  *BackupItemActionPlugin
 	volumeSnapshotter *VolumeSnapshotterPlugin
 	objectStore       *ObjectStorePlugin
@@ -99,12 +98,10 @@ type server struct {
 // NewServer returns a new Server
 func NewServer() Server {
 	log := newLogger()
-	features := veleroflag.NewStringArray()
 
 	return &server{
 		log:               log,
 		logLevelFlag:      logging.LogLevelFlag(log.Level),
-		featureSet:        &features,
 		backupItemAction:  NewBackupItemActionPlugin(serverLogger(log)),
 		volumeSnapshotter: NewVolumeSnapshotterPlugin(serverLogger(log)),
 		objectStore:       NewObjectStorePlugin(serverLogger(log)),
@@ -116,7 +113,6 @@ func NewServer() Server {
 
 func (s *server) BindFlags(flags *pflag.FlagSet) Server {
 	flags.Var(s.logLevelFlag, "log-level", fmt.Sprintf("The level at which to log. Valid values are %s.", strings.Join(s.logLevelFlag.AllowedValues(), ", ")))
-	flags.Var(s.featureSet, "features", "List of feature flags for this plugin")
 	s.flagSet = flags
 	s.flagSet.ParseErrorsWhitelist.UnknownFlags = true