Slightly change the explanation of response variables

When an action does return a result the user can save this in a variable that can be used in the next actions in the sequence.

That variable is created by simply naming it in the action. This should be made clearer in the two strings that describe this option.

By using "… name for a variable …" becomes inherently clear that this variable will be created by the action.

src/translations/en.json

@@ -3415,8 +3415,8 @@
                 "service": {
                   "label": "Perform action",
                   "response_variable": "Response variable",
-                  "has_optional_response": "This action can return a response, if you want to use the response, enter the name of a variable the response will be saved in",
-                  "has_response": "This action returns a response, enter the name of a variable the response will be saved in",
+                  "has_optional_response": "This action can return a response, if you want to use the response, enter the name for a variable the response will be saved in",
+                  "has_response": "This action returns a response, enter the name for a variable the response will be saved in",
                   "description": {
                     "picker": "Previously known as call service.",
                     "service_based_on_template": "Perform an action based on a template on {targets}",