* Update Agent Auth with GCP to use new SignJWT endpoint
* use iamcredentials name instead of renaming the package on import
* add changelog
* Update changelog/11473.txt
Co-authored-by: Theron Voran <tvoran@users.noreply.github.com>
Co-authored-by: Theron Voran <tvoran@users.noreply.github.com>
The result will still pass gofmtcheck and won't trigger additional
changes if someone isn't using goimports, but it will avoid the
piecemeal imports changes we've been seeing.
