feat(sms): Fully roll out SMS in BE, DK, NL (#6190), r=@vbudhram
feat(sms): Fully roll out SMS in BE, DK, NL (#6190), r=@vbudhram

All 3 countries have a good conversion rate,
time to open up SMS to everyone in those countries!

fixes #6189
mozilla/fxa-content-server,mozilla/fxa-content-server,shane-tomlinson/fxa-content-server,shane-tomlinson/fxa-content-server,mozilla/fxa-content-server,shane-tomlinson/fxa-content-server