"Add all cameras" checkbox is missing in Quality settings when streaming mipmaps feature is enabled.

Steps to reproduce

1) Create new project
2) Edit > Quality Settings > Check "Streaming mipmaps feature" checkbox.
3) Observe that "Add all cameras" checkbox is missing.

Note:

1) Streaming mipmaps feature was introduced in 2018.2.a1
2) Refer to the screenshot attached from the documentation.

Reproducible on: 2018.2.a1

Environment: Occurs both on Windows and Mac