Fix all ACI examples to use delegate_to (#43439)

This is to avoid users connecting to the APIC using SSH, which is likely
to fail. In the ACI documentation (linked from every module) we go into
more details on how people are supposed to work with the modules..

lib/ansible/modules/network/aci/aci_contract_subject.py

@@ -92,6 +92,7 @@ EXAMPLES = r'''
     priority: level1
     dscp: unspecified
     state: present
+  register: query_result
 
 - name: Remove a contract subject
   aci_contract_subject:
@@ -102,6 +103,7 @@ EXAMPLES = r'''
     contract: web_to_db
     subject: default
     state: absent
+  delegate_to: localhost
 
 - name: Query a contract subject
   aci_contract_subject:
@@ -112,6 +114,8 @@ EXAMPLES = r'''
     contract: web_to_db
     subject: default
     state: query
+  delegate_to: localhost
+  register: query_result
 
 - name: Query all contract subjects
   aci_contract_subject:
@@ -119,6 +123,8 @@ EXAMPLES = r'''
     username: admin
     password: SomeSecretPassword
     state: query
+  delegate_to: localhost
+  register: query_result
 '''
 
 RETURN = r'''