teams-service iam v2 force upgrade clean up

[susanev]

deets

• drop the v1 server i think this is already done, someone should confirm
• Change protobuf validation for team IDs to match all other resources (^[a-z0-9-_]{1,64}$) and remove the comment "We can't make this more restrictive until we migrate existing IDs post-GA," which appears multiple times in teams.proto. -> to be resolved in use validation lib in teams server #3499
• double check the service for any remaining v1/v2 conditional handling