In the Next Gen Configuration section, the feedback notification messages should be cleared after another one is displayed

Short Description: In the Next Gen Configuration section, the feedback notification messages should be cleared after another one is displayed.

Steps to Reproduce:

1 - Navigate to Next Gen Project Settings -> Apps -> XRay Settings -> Next Gen Configuration option.

2 - Map two XRay issues with the same issue type and press Save button.

3 - Now put different issue types into different XRay issues and press Save button. 

4 - Compare this situation with a similar one in the Default Columns Layout option.

Actual Result: On step 2, an error message is displayed and on step 3, a success message is displayed, both co-existing at the same time in the screen.

Expected Result: When the success message is displayed, the previous error message should be cleared.