Set default value for HSTS options to None

The default value of these options was False, it means that
octaviaclient sends {'attr': False} to the Octavia API even if it is not
required.

Setting the default value to None, the attribute will not be send when
it is not needed.
It also fixes a potential issue when using recent python-octaviaclient
release with an old octavia release that doesn't support HSTS.

Closes-Bug: #2037253

Change-Id: Ica89bbd257216ef423afc44e0c81498037aece20
(cherry picked from commit db6b62ebdd)

octaviaclient/osc/v2/listener.py

@@ -215,6 +215,7 @@ class CreateListener(command.ShowOne):
             '--hsts-include-subdomains',
             action='store_true',
             dest='hsts_include_subdomains',
+            default=None,
             help="Define whether the includeSubDomains directive should be "
                  "added to the Strict-Transport-Security HTTP response "
                  "header."
@@ -223,6 +224,7 @@ class CreateListener(command.ShowOne):
             '--hsts-preload',
             action='store_true',
             dest='hsts_preload',
+            default=None,
             help="Define whether the preload directive should be "
                  "added to the Strict-Transport-Security HTTP response "
                  "header."

octaviaclient/tests/unit/osc/v2/test_listener.py

@@ -195,6 +195,9 @@ class TestListenerCreate(TestListener):
         ]
 
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+        self.assertIsNone(parsed_args.hsts_include_subdomains)
+        self.assertIsNone(parsed_args.hsts_preload)
+        self.assertIsNone(parsed_args.hsts_max_age)
         self.cmd.take_action(parsed_args)
         self.api_mock.listener_create.assert_called_with(
             json={'listener': self.listener_info})

releasenotes/notes/remove-unneeded-attributes-in-listener-create-2e7cb2de281ac7fe.yaml

@@ -0,0 +1,8 @@
+---
+fixes:
+  - |
+    Removed unneeded attributes that could have been passed to the API when
+    calling "listener create", hsts_include_subdomains and hsts_preload were
+    passed even when not used.
+    It fixes an issue when using a recent python-octaviaclient release with
+    older Octavia releases (without this HSTS feature).