docs: fix filename in first-app (angular#50207)

Same mistake as angular#50204 but a different file.

PR Close angular#50207

aio/content/tutorial/first-app/first-app-lesson-09.md

@@ -71,7 +71,7 @@ For now, your app's new service uses the data that has, so far, been created loc
 In the **Edit** pane of your IDE:
 
 1.  In `src/app/home/home.component.ts`, from `HomeComponent`, copy the `housingLocationList` variable and its array value.
-1.  In `src/app/housing.servivce.ts`:
+1.  In `src/app/housing.service.ts`:
     1.  Inside the `HousingService` class, paste the variable that you copied from `HomeComponent` in the previous step.
     1.  Inside the `HousingService` class, paste these functions after the data you just copied.
         These functions allow dependencies to access the service's data.