Fix and test data migration error from DAB RBAC (#15138)

* Fix and test data migration error from DAB RBAC

* Fix up migration test

* Fix custom method bug

* Fix another fat fingered bug

awx/main/tests/functional/test_migrations.py

@@ -1,6 +1,7 @@
 import pytest
 
 from django_test_migrations.plan import all_migrations, nodes_to_tuples
+from django.utils.timezone import now
 
 """
 Most tests that live in here can probably be deleted at some point. They are mainly
@@ -68,3 +69,19 @@ class TestMigrationSmoke:
         bar_peers = bar.peers.all()
         assert len(bar_peers) == 1
         assert fooaddr in bar_peers
+
+    def test_migrate_DAB_RBAC(self, migrator):
+        old_state = migrator.apply_initial_migration(('main', '0190_alter_inventorysource_source_and_more'))
+        Organization = old_state.apps.get_model('main', 'Organization')
+        User = old_state.apps.get_model('auth', 'User')
+
+        org = Organization.objects.create(name='arbitrary-org', created=now(), modified=now())
+        user = User.objects.create(username='random-user')
+        org.read_role.members.add(user)
+
+        new_state = migrator.apply_tested_migration(
+            ('main', '0192_custom_roles'),
+        )
+
+        RoleUserAssignment = new_state.apps.get_model('dab_rbac', 'RoleUserAssignment')
+        assert RoleUserAssignment.objects.filter(user=user.id, object_id=org.id).exists()