refactor(feature): use OptionCodename[] type for relatedOptions

This CL also fixes the relatedOptions for the features which have
already been migrated to the new architecture.

Change-Id: I457e16af132eaa855b3386237a5dc692eb8e0d91
diff --git a/src/features/extraInfo/extraInfo.feature.ts b/src/features/extraInfo/extraInfo.feature.ts
index f7f9f66..63f0818 100644
--- a/src/features/extraInfo/extraInfo.feature.ts
+++ b/src/features/extraInfo/extraInfo.feature.ts
@@ -1,5 +1,6 @@
 import Feature from '../../common/architecture/features/Feature';
 import { ConcreteScript } from '../../common/architecture/scripts/Script';
+import { OptionCodename } from '../../common/optionsPrototype';
 import CCExtraInfoDependencySetUpScript from './scripts/ccExtraInfoDependencySetUp.script';
 import CCExtraInfoInjectScript from './scripts/ccExtraInfoInject.script';
 import CCExtraInfoMainScript from './scripts/ccExtraInfoMain.script';
@@ -14,5 +15,5 @@
   ];
 
   readonly codename = 'extraInfo';
-  readonly relatedOptions: string[] = [];
+  readonly relatedOptions: OptionCodename[] = ['extrainfo', 'perforumstats'];
 }