civil: add license comment
civil: add license comment

Change-Id: I9af2a84e8649e4f73edf7b6bb0d058e42587122e
Reviewed-on: https://code-review.googlesource.com/9569
Reviewed-by: Ross Light <dfccc06f14414bff5a59be7fc90abf4404b47fc8@google.com>

michael-grosshans/google-cloud-go,googleapis/google-cloud-go,googleapis/google-cloud-go,googleapis/google-cloud-go,googleapis/google-cloud-go,michael-grosshans/google-cloud-go