Set default=no in import_role and include_role for private. Fixes #21077 (#39566)

lib/ansible/modules/utilities/logic/import_role.py

@@ -53,6 +53,7 @@ options:
       - If C(yes) the variables from C(defaults/) and C(vars/) in a role will not be made available to the rest of the
         play.
     type: bool
+    default: 'no'
 notes:
   - Handlers are made available to the whole play.
 '''

lib/ansible/modules/utilities/logic/include_role.py

@@ -52,6 +52,7 @@ options:
       - If C(yes) the variables from C(defaults/) and C(vars/) in a role will not be made available to the rest of the
         play.
     type: bool
+    default: 'no'
 notes:
   - Handlers are made available to the whole play.
   - Before Ansible 2.4, as with C(include), this task could be static or dynamic, If static, it implied that it won't