Always use EE resolving logic

awx/main/utils/execution_environments.py

@@ -0,0 +1,9 @@
+from django.conf import settings
+
+from awx.main.models.execution_environments import ExecutionEnvironment
+
+
+def get_execution_environment_default():
+    if settings.DEFAULT_EXECUTION_ENVIRONMENT is not None:
+        return settings.DEFAULT_EXECUTION_ENVIRONMENT
+    return ExecutionEnvironment.objects.filter(organization=None, managed_by_tower=True).first()