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/common/architecture/features/Feature.ts b/src/common/architecture/features/Feature.ts
index c14c338..e1a3389 100644
--- a/src/common/architecture/features/Feature.ts
+++ b/src/common/architecture/features/Feature.ts
@@ -1,3 +1,4 @@
+import { OptionCodename } from '../../optionsPrototype';
 import Script, { ConcreteScript } from '../scripts/Script';
 
 export default abstract class Feature {
@@ -11,7 +12,7 @@
   /**
    * Options which control the behavior of this feature.
    */
-  abstract readonly relatedOptions: string[];
+  abstract readonly relatedOptions: OptionCodename[];
 
   /**
    * Uninitialized scripts which are associated with the feature.