Add http.payloadTimeout config option (#177309)

## Summary

Fix https://github.com/elastic/kibana/issues/177138

- Add a `http.payloadTimeout` configuration option, to control the
payload timeout
- Set the default value for this option to `20s` (was `10s` previously)

packages/kbn-cli-dev-mode/src/config/http_config.ts

@@ -30,6 +30,9 @@ export const httpConfigSchema = schema.object(
     socketTimeout: schema.number({
       defaultValue: 120000,
     }),
+    payloadTimeout: schema.number({
+      defaultValue: 20000,
+    }),
     cors: schema.object({
       enabled: schema.boolean({ defaultValue: false }),
       allowCredentials: schema.boolean({ defaultValue: false }),
@@ -53,6 +56,7 @@ export class HttpConfig implements IHttpConfig {
   shutdownTimeout: Duration;
   keepaliveTimeout: number;
   socketTimeout: number;
+  payloadTimeout: number;
   cors: ICorsConfig;
   ssl: ISslConfig;
   restrictInternalApis: boolean;
@@ -64,6 +68,7 @@ export class HttpConfig implements IHttpConfig {
     this.maxPayload = rawConfig.maxPayload;
     this.shutdownTimeout = rawConfig.shutdownTimeout;
     this.keepaliveTimeout = rawConfig.keepaliveTimeout;
+    this.payloadTimeout = rawConfig.payloadTimeout;
     this.socketTimeout = rawConfig.socketTimeout;
     this.cors = rawConfig.cors;
     this.ssl = new SslConfig(rawConfig.ssl);

packages/kbn-cli-dev-mode/src/integration_tests/base_path_proxy_server.test.ts

@@ -39,6 +39,7 @@ describe('BasePathProxyServer', () => {
       shutdownTimeout: moment.duration(30, 'seconds'),
       keepaliveTimeout: 1000,
       socketTimeout: 1000,
+      payloadTimeout: 1000,
       cors: {
         enabled: false,
         allowCredentials: false,