internal/licenses: add more filenames
internal/licenses: add more filenames

Add all filenames used by at least 10 latest-version modules that
have none of the previously acceptable filenames.

Change-Id: I1e79d3187901d2c29862ae0584696e3dbbb2462b
Reviewed-on: https://team-review.git.corp.google.com/c/golang/discovery/+/663153
Reviewed-by: Julie Qiu <e6cb64861edcc38971590ff27c111e0e672de045@google.com>

golang/pkgsite,golang/pkgsite,golang/pkgsite,golang/pkgsite