VPN-5749: Enable annual upgrades on Stage desktop

[lesleyjanenorton]

Description

Per a request from QA, this PR enables the annualUpgrade feature on Stage desktop only. This means that the upgrade path in the Subscription Management view should now be visible by default for someone who:

• Is on stage &&
• Is on a desktop device &&
• Has a monthly subscription which was purchased through SubPlat (not the App Store, not the Play Store)

Reference

VPN-5749

Checklist

• My code follows the style guidelines for this project
• I have not added any packages that contain high risk or unknown licenses (GPL, LGPL, MPL, etc. consult with DevOps if in question)
• I have performed a self review of my own code
• I have commented my code PARTICULARLY in hard to understand areas
• I have added thorough tests where needed

[mcleinman]

👍🏻