review-dev has a new label called 'workflow' that combines approved and wip labels.
Updating the trigger for gate pipeline to match.
The gerrit workflow label is defined as:
[label "Workflow"]
function = MaxWithBlock
copyMinScore = false
copyAllScoresOnTrivialRebase = false
copyAllScoresIfNoCodeChange = false
value = -1 Work in progress
value = 0 Ready for reviews
value = +1 Approved
Change-Id: Ieb7e2dde49cd64f2aa3dbf939c391492d73ed886