How to reproduce:
1. Create a new 3D template project
2. Create a prefab from the Sample Scene's Main camera and save the Scene
3. Upgrade the project to use URP
4. Open the Main camera prefab
5. Exit from Prefab mode back to the Scene view

Expected result: The Main camera in the Scene has 1 Universal Additional Camera component and is functioning properly
Actual result: The Main camera in the Scene now has 2 Universal Additional Camera components and is no longer functioning

Reproducible with: 2019.3.13f1(7.1.2, 7.3.1), 2020.3.16f1(10.6.0), 2021.1.15f1(11.0.0), 2021.2.0b7(12.0.0), 2022.1.0a6(12.0.0)
Could not test with: 2018.4.22f1(RP packages were in early preview stage)

Workaround: Delete the Camera object from the Scene and re-add its Prefab

Notes:
1. Sometimes the issue also affects non-prefab objects in the Scene if the Scene was saved before Render Pipeline Asset is removed
2. Affects both URP and HDRP. When HDRP is used, duplicate HD Additional Camera Data component is created, however, the duplicate can be manually deleted unlike when using URP. Tested with 2020.1.0b9 and HDRP 8.1.0
3. Universal Additional Camera Data component for URP was introduced in 7.1.2 (2019.3.0b4)