add migration file to setup managed credential types to add the new credential type

Signed-off-by: Hao Liu <haoli@redhat.com>

awx/main/migrations/0165_added_contentsigning_to_project_model.py

@@ -3,6 +3,14 @@
 from django.db import migrations, models
 import django.db.models.deletion
 
+from awx.main.models import CredentialType
+from awx.main.utils.common import set_current_apps
+
+
+def setup_tower_managed_defaults(apps, schema_editor):
+    set_current_apps(apps)
+    CredentialType.setup_tower_managed_defaults(apps)
+
 
 class Migration(migrations.Migration):
 
@@ -28,4 +36,5 @@ class Migration(migrations.Migration):
                 to='main.credential',
             ),
         ),
+        migrations.RunPython(setup_tower_managed_defaults),
     ]