In-App Updates: Track events

[momo-ozawa]

Part of https://github.com/Automattic/wordpress-mobile/issues/55
Part of https://github.com/Automattic/wordpress-mobile/issues/56

Description

• Adds event tracking for in-app updates

How to test

Flexible update

Precondition: In Xcode, change the app version to something lower than the current app store version, e.g. 24.6

• ✅ Verify in_app_update_shown <type: flexible> is tracked when the prompt is shown
• ✅ Verify Tracked: in_app_update_dismissed <> is tracked when the "Cancel" is tapped
• ✅ Verify Tracked: in_app_update_accepted <type: flexible> is tracked when the "Update" is tapped

Blocking update

Precondition: In Xcode, change the app version to something lower than the current app store version, e.g. 24.6

Precondition: Change the in app update remote config value to the current app store version

• ✅ Verify in_app_update_shown <type: blocking> is tracked when the prompt is shown
• ✅ Verify Tracked: in_app_update_accepted <type: blocking> is tracked when the "Update" is tapped

Todo

• Validate / register events

Regression Notes

1. Potential unintended areas of impact
   n/a

2. What I did to test those areas of impact (or what existing automated tests I relied on)
   n/a

3. What automated tests I added (or what prevented me from doing so)
   n/a

PR submission checklist:

• I have completed the Regression Notes.
• I have considered adding unit tests for my changes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

[dangermattic]

	1 Warning
⚠️	View files have been modified, but no screenshot or video is included in the pull request. Consider adding some for clarity.

Generated by 🚫 Danger

[wpmobilebot]

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

	App Name	WordPress Alpha
	Configuration	Release-Alpha
	Build Number	pr23207-44887ae
	Version	24.8
	Bundle ID	org.wordpress.alpha
	Commit	44887ae
	App Center Build	WPiOS - One-Offs #9908

Automatticians: You can use our internal self-serve MC tool to give yourself access to App Center if needed.

[wpmobilebot]

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

	App Name	Jetpack Alpha
	Configuration	Release-Alpha
	Build Number	pr23207-44887ae
	Version	24.8
	Bundle ID	com.jetpack.alpha
	Commit	44887ae
	App Center Build	jetpack-installable-builds #8956

Automatticians: You can use our internal self-serve MC tool to give yourself access to App Center if needed.