Fix volume sync order. (zalando#1340)

Author: Jan-M

pkg/cluster/sync.go

@@ -53,17 +53,18 @@ func (c *Cluster) Sync(newSpec *acidv1.Postgresql) error {
 		return err
 	}
 
+	// sync volume may already transition volumes to gp3, if iops/throughput or type is specified
+	if err = c.syncVolumes(); err != nil {
+		return err
+	}
+
 	if c.OpConfig.EnableEBSGp3Migration {
 		err = c.executeEBSMigration()
 		if nil != err {
 			return err
 		}
 	}
 
-	if err = c.syncVolumes(); err != nil {
-		return err
-	}
-
 	if err = c.enforceMinResourceLimits(&c.Spec); err != nil {
 		err = fmt.Errorf("could not enforce minimum resource limits: %v", err)
 		return err