Merge role params into variables separately from other variables

Fixes #13617

lib/ansible/playbook/role/__init__.py

@@ -265,6 +265,12 @@ class Role(Base, Become, Conditional, Taggable):
                 inherited_vars = combine_vars(inherited_vars, parent._role_params)
         return inherited_vars
 
+    def get_role_params(self):
+        params = {}
+        for dep in self.get_all_dependencies():
+            params = combine_vars(params, dep._role_params)
+        return params
+
     def get_vars(self, dep_chain=[], include_params=True):
         all_vars = self.get_inherited_vars(dep_chain, include_params=include_params)
 

lib/ansible/vars/__init__.py

@@ -308,6 +308,7 @@ class VariableManager:
 
             if not C.DEFAULT_PRIVATE_ROLE_VARS:
                 for role in play.get_roles():
+                    all_vars = combine_vars(all_vars, role.get_role_params())
                     all_vars = combine_vars(all_vars, role.get_vars(include_params=False))
 
         if task: