Handle upsell flow in the End of Year flow

[MiSikora]

Description

This PR adds handling of the upsell flow and story navigation.

Testing Instructions

Note

Test this with the release variant so you can complete a purchase.

1. Apply this patch.
2. Sign in with a paid account.
3. Start Playback 2024.
4. Verify that navigation works as expected.
5. Navigate back to the Profile tab.
6. Sign out.
7. Sign up with a new account.
8. Start Playback 2024.
9. Confirm that navigation works, but note that navigating forward on the Plus Interstitial story skips two stories and jumps to the Ending story.
10. Navigating backwards on the Ending story should return to the Plus Interstitial story.
11. Tap the upsell button.
12. Verify that the upsell flow starts.
13. Close the upsell flow.
14. Confirm that you are still on the Plus Interstitial story.
15. Start the upsell flow again.
16. Complete the upsell flow.
17. After onboarding completes, you should see the Year vs Year story, and the Plus Interstitial story should no longer appear in the Playback 2024 flow. Navigation should work like in the 4th step.

Checklist

• If this is a user-facing change, I have added an entry in CHANGELOG.md
• Ensure the linter passes (./gradlew spotlessApply to automatically apply formatting/linting)
• I have considered whether it makes sense to add tests for my changes
• All strings that need to be localized are in modules/services/localization/src/main/res/values/strings.xml
• Any jetpack compose components I added or changed are covered by compose previews
• ~I have updated (or requested that someone edit) the spreadsheet to reflect any new or changed analytics.

[dangermattic]

	1 Warning
⚠️	Class StoryChanger is missing tests, but unit-tests-exemption label was set to ignore this.

Generated by 🚫 Danger

[wpmobilebot]

📲 You can test the changes from this Pull Request in 📱 Mobile by scanning the QR code below to install the corresponding build.

	App Name	📱 Mobile
	Build Type	debugProd
	Commit	eec3a3f
	Direct Download	pocketcasts-app-prototype-build-pr3066-eec3a3f.apk

📲 You can test the changes from this Pull Request in 🚗 Automotive by scanning the QR code below to install the corresponding build.

	App Name	🚗 Automotive
	Build Type	debugProd
	Commit	eec3a3f
	Direct Download	pocketcasts-automotive-prototype-build-pr3066-eec3a3f.apk

📲 You can test the changes from this Pull Request in ⌚ Wear by scanning the QR code below to install the corresponding build.

	App Name	⌚ Wear
	Build Type	debugProd
	Commit	eec3a3f
	Direct Download	pocketcasts-wear-prototype-build-pr3066-eec3a3f.apk