Media CDN now supports origin redirect following and origin header overrides in Preview

## Feature Media CDN now supports origin redirect following and origin header overrides in [Preview](https://cloud.google.com/products#product-launch-stages). You can improve performance and caching for frequent redirection by configuring origin redirect following in Media CDN. When configured, Media CDN follows origin redirect responses and caches the final retrieved object. For more information, see [Configure following origin redirects](https://cloud.google.com/media-cdn/docs/origins#configure-following-origin-redirects). You can also configure Media CDN to manipulate headers on a per-origin basis, which supports distinct host rewrites and static authorization headers for failover origins. For more information, see [Failover and timeouts](https://cloud.google.com/media-cdn/docs/origins#failover-and-timeouts) and [Example: Failover with redirect following](https://cloud.google.com/media-cdn/docs/origins#failover-with-redirect-following).