The default bootstrap styling for table rows uses the same classes as
alerts (warning, danger etc). Rather than layering additional logic
around this with a new class, we should just fall back to the documented
boostrap method.
Also resets the warning colour to its default bootstrap variable, rather
than carrying an altered version.
Change-Id: I3472244fcbbd121a8de48d78084554760dab6385
Closes-Bug: 1615632