Merge branch 'build-scroll-controls-on-complete' into 'master'

Shows build scroll buttons after build is complete

## What does this MR do?

Shows the build scroll buttons whenever there is a build trace. Previously they were only shown when the build was active.

## What are the relevant issue numbers?

Closes #18515 

## Screenshots (if relevant)

![Screen_Shot_2016-06-13_at_11.42.42](/uploads/6e0577f46a0cc7b4f2f13b17c85d97da/Screen_Shot_2016-06-13_at_11.42.42.png)

See merge request !4621