fix(storage): remove duplicate routing header (googleapis#11534)

Appendable writes were duplicating the x-goog-request-params header which caused issues server side. Remove this.

For append writes we need to include appendable=true and an optional routing token in this header.

Author: tritone

storage/grpc_client.go

@@ -1744,7 +1744,14 @@ func (c *grpcStorageClient) OpenWriter(params *openWriterParams, opts ...storage
 					return err
 				}
 
-				err = run(bucketContext(gw.ctx, gw.bucket), uploadBuff, gw.settings.retry, s.idempotent)
+				// Add routing headers to the context metadata for single-shot and resumable
+				// writes. Append writes need to set this at a lower level to pass the routing
+				// token.
+				bctx := gw.ctx
+				if !gw.append {
+					bctx = bucketContext(bctx, gw.bucket)
+				}
+				err = run(bctx, uploadBuff, gw.settings.retry, s.idempotent)
 				if err != nil {
 					return err
 				}