Renamed a couple of Flow jobs to follow the convention
Added per-browser tags to MobileFrontend builds

Paired with Chris McMahon.

Bug: 62846
Fixed browser for several Jenkins jobs

Some jobs were using the wrong browser.

Reported at
https://github.com/zeljkofilipin/jenkins-job-builder-config/issues/5
Added browser specific tags to ContentTranslation Cucumber feature

Paired with Kartik Mistry.

Bug: 62477
Replaced browser_version JJB variable with BROWSER_TAG shell variable