New hosted site: Add selected add-ons to the cart

[zaguiini]

Fixes DOTCOM-10648.

Proposed Changes

Fixes a bug where the add-on wasn't being added to the cart within /setup/new-hosted-site.

Testing Instructions

Enter /setup/new-hosted-site and verify that picking a plan with a storage add-on lists reflects at checkout.

[github-actions]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-141717

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-141717&env=jetpack

Automattic for Agencies live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-141717&env=a8c-for-agencies

[matticbot]

Here is how your PR affects size of JS and CSS bundles shipped to the user's browser:

Sections (~31 bytes added 📈 [gzipped])

Details

name                  parsed_size           gzip_size
new-hosted-site-flow        +48 B  (+0.0%)      +31 B  (+0.1%)

Sections contain code specific for a given set of routes. Is downloaded and parsed only when a particular route is navigated to.

Legend

What is parsed and gzip size?

Parsed Size: Uncompressed size of the JS and CSS files. This much code needs to be parsed and stored in memory.
Gzip Size: Compressed size of the JS and CSS files. This much data needs to be downloaded over network.

Generated by performance advisor bot at iscalypsofastyet.com.

[matticbot]

This PR modifies the release build for the following Calypso Apps:

For info about this notification, see here: PCYsg-OT6-p2

• blaze-dashboard
• notifications
• wpcom-block-editor

To test WordPress.com changes, run install-plugin.sh $pluginSlug dotcom-10648-new-hosted-site-flow-doesnt-add-storage-add-ons-to-the-cart on your sandbox.

[paulopmt1]

It's working as expected, thanks for fixing it!
Can we also add a test to ensure this won't happen again?

[zaguiini]

Of course, @paulopmt1. I'll add it as a follow-up.