Redundant *+* button in *Discount Priorities and Exclusions* screen

Description

Steps to reproduce:

1. Go to new Marketing UI.
2. Click on Discount Priorities and Exclusions > The Discount Priorities and Exclusions screen displays.

Expected: There is no + button to create new Campaign/Discount. User cannot create new Campaign/Discount from this screen.
Actual: There is + button in this screen. If clicking on this button, a blank label is displayed.

Note: This bug does not occur in 10.2.0. In 10.2.0, there is no + button on the Discount Priorities and Exclusions screen.