rename return var to avoid conflicts

fixes #22323

lib/ansible/modules/cloud/docker/docker_container.py

@@ -611,8 +611,9 @@ EXAMPLES = '''
 '''
 
 RETURN = '''
-ansible_docker_container:
+docker_container:
     description:
+      - Before 2.3 this was 'ansible_docker_container' but was renamed due to conflicts with the connection plugin.
       - Facts representing the current state of the container. Matches the docker inspection output.
       - Note that facts are not part of registered vars but accessible directly.
       - Empty if C(state) is I(absent)
@@ -1675,7 +1676,7 @@ class ContainerManager(DockerBaseClass):
             self.results['diff'] = self.diff
 
         if self.facts:
-            self.results['ansible_facts'] = {'ansible_docker_container': self.facts}
+            self.results['ansible_facts'] = {'docker_container': self.facts}
 
     def present(self, state):
         container = self._get_container(self.parameters.name)