Fix deploy prompt with existing Subscription UI

[gonzaloriestra]

WHY are these changes introduced?

If you create a Subscription UI and deploy, the next time it keeps showing it as new (but it's already released)

WHAT is this pull request doing?

Add a missing identifier for that kind of extension, so it matches the remote one.

How to test your changes?

• p shopify app generate extension --template subscription_ui
• p shopify app deploy
• p shopify app deploy

Measuring impact

How do we know this change was effective? Please choose one:

• n/a - this doesn't need measurement, e.g. a linting rule or a bug-fix
• Existing analytics will cater for this addition
• PR includes analytics changes to measure impact

Checklist

• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've considered possible documentation changes
• I've made sure that any changes to dev or deploy have been reflected in the internal flowchart.

[github-actions]

Thanks for your contribution!

Depending on what you are working on, you may want to request a review from a Shopify team:

• Themes: @shopify/advanced-edits
• UI extensions: @shopify/ui-extensions-cli
  • Checkout UI extensions: @shopify/checkout-ui-extensions-api-stewardship
• Hydrogen: @shopify/hydrogen
• Other: @shopify/app-management

[github-actions]

Coverage report

St.❔	Category	Percentage	Covered / Total
🟡	Statements	72.03% (-0.08% 🔻)	7369/10231
🟡	Branches	68.9% (-0.11% 🔻)	3612/5242
🟡	Functions	71.54% (-0.07% 🔻)	1953/2730
🟡	Lines	73.29% (-0.08% 🔻)	6950/9483

Show files with reduced coverage 🔻

St.❔	File	Statements	Branches	Functions	Lines
🔴	... / system.ts	5.26% (-21.05% 🔻)	0% (-20.69% 🔻)	25% (-25% 🔻)	5.56% (-22.22% 🔻)

Test suite run success

1700 tests passing in 792 suites.

Report generated by 🧪jest coverage report action from ec0854a