A teacher can add a material to other teacher's course

[Tatyana-Kravchenko]

Steps to reproduce
Teacher created course (id: {{courseIdForMaterials}})
Post {{host}}/api/v1/courses

{
  "title": "How to create test cases1 {{coursePostfix}}",
  "description": "Basic course about test design technique",
  "visible": true,
  "categoryId": {{categoryIdForMaterial}}
}

Teacher 2 tries to add a material in teacher's course
POST {{host}}/api/v1/courses/{{courseIdForMaterials}}/materials
Request Body

{
  "title": "Additional material {{materialPostfix}}",
  "data": "stringstri",
  "order": 0
}

Actual behavior

1. Status code is 200
2. Response time is less than 1000 ms
3. Teacher 2 added a new material in the teacher's course

Expected behavior

1. Status code is 403
2. Response time is less than 1000 ms
3. Teacher 2 can't add a new material in the teacher's course
4. The error text message ("You're not owner of this course, you can't change/remove it") is correct
   Screenshots
   If applicable, add screenshots to help explain your problem.
   
   
   

[viraxslot]

@Tatyana-Kravchenko I think about collaboration. What do you think if we convert this bug to a feature? Maybe a teacher can invite the other teacher to work together on a course.