fix a few issues in credential type kind validation

- fix a typo from `network` to `net`
- properly update OPTIONS for CredentialTypes to reflect allowed `kind`
  values for POST/PUT/

see: #6959

awx/main/tests/functional/api/test_credential_type.py

@@ -143,6 +143,28 @@ def test_create_managed_by_tower_readonly(get, post, admin):
     assert response.data['results'][0]['managed_by_tower'] is False
 
 
+@pytest.mark.django_db
+@pytest.mark.parametrize('kind', ['cloud', 'net'])
+def test_create_valid_kind(kind, get, post, admin):
+    response = post(reverse('api:credential_type_list'), {
+        'kind': kind,
+        'name': 'My Custom Type',
+        'inputs': {
+            'fields': [{
+                'id': 'api_token',
+                'label': 'API Token',
+                'type': 'string',
+                'secret': True
+            }]
+        },
+        'injectors': {}
+    }, admin)
+    assert response.status_code == 201
+
+    response = get(reverse('api:credential_type_list'), admin)
+    assert response.data['count'] == 1
+
+
 @pytest.mark.django_db
 @pytest.mark.parametrize('kind', ['ssh', 'vault', 'scm', 'insights'])
 def test_create_invalid_kind(kind, get, post, admin):