added bash header to remove and add_licenses

Author: mossmana

update_licenses.yaml

@@ -17,9 +17,12 @@ remove_licenses:
     **/
   #2
   - |-
+    #!/bin/bash
+    #
     # Copyright <value> The Chromium Authors. All rights reserved.
     # Use of this source code is governed by a BSD-style license that can be
     # found in the LICENSE file.
+    #!/bin/bash
   #3
   - |-
     <!--
@@ -57,6 +60,8 @@ add_licenses:
     **/
   #2
   - |-
+    #!/bin/bash
+    #
     # Copyright <value> The Flutter Authors
     # Use of this source code is governed by a BSD-style license that can be
     # found in the LICENSE file or at https://developers.google.com/open-source/licenses/bsd.