Protected ReadonlycustomizationProtected ReadonlypreferenceProtected ReadonlyworkspaceProtectedupdateUpdates the template configuration in the customization service. If a specific preference name is provided, only that configuration aspect is updated.
OptionalchangedPreference: stringOptional name of the preference that changed
Called when the application is started. The application shell is not attached yet when this method runs. Should return a promise if it runs asynchronously.