Add MaximumVaultTimeout policy type (#480)

electron/src/services/electronPlatformUtils.service.ts

@@ -88,10 +88,6 @@ export class ElectronPlatformUtilsService implements PlatformUtilsService {
         return Promise.resolve(false);
     }
 
-    lockTimeout(): number {
-        return null;
-    }
-
     launchUri(uri: string, options?: any): void {
         shell.openExternal(uri);
     }