Currently it is not possible to distinguish between tracing of the same
*Service type whenever there are multiple of them. Now the instance_name
of ServiceBuilder is passed into the *Service and used in the existing
instrument as the `instance_name` field.
Places that did not already have a instance_name in its context use
`"default"`. In tests I used `"test"`.
Change-Id: Ia20bf2a7bb849a781e370d087ba7ddb3be79f654
Reviewed-on: https://cl.tvl.fyi/c/depot/+/12739
Tested-by: BuildkiteCI
Autosubmit: Bob van der Linden <bobvanderlinden@gmail.com>
Reviewed-by: flokli <flokli@flokli.de>