Service account policy UI (#1519)

* saving

* service account policy UI

* fixing warning

* Update portal-ui/src/screens/Console/Account/ServiceAccountPolicy.tsx

Co-authored-by: Daniel Valdivia <18384552+dvaldivia@users.noreply.github.com>

* fixing comment

Co-authored-by: Daniel Valdivia <18384552+dvaldivia@users.noreply.github.com>
Co-authored-by: Lenin Alevski <alevsk.8772@gmail.com>

restapi/user_service_accounts.go

@@ -19,6 +19,7 @@ package restapi
 import (
 	"bytes"
 	"context"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"strings"
@@ -366,6 +367,11 @@ func getServiceAccountPolicy(ctx context.Context, userClient MinioAdmin, accessK
 	if err != nil {
 		return "", err
 	}
+	var policy iampolicy.Policy
+	json.Unmarshal([]byte(serviceAccountInfo.Policy), &policy)
+	if policy.Statements == nil {
+		return "", nil
+	}
 	return serviceAccountInfo.Policy, nil
 }