Cleanup angle_libs_suffix in BUILD.gn. We can use output_name instead of repeating the libs suffix in the GN files. Bug: angleproject:3611 Change-Id: Ic87c1378aac8be8e1aec695ddbe5c8ec2ed3187b Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1678403 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Tim Van Patten <timvp@google.com> Reviewed-by: Geoff Lang <geofflang@chromium.org>