Finalize Analytics Usage Tracking

[shiki]

This enhances #5503 so that it can be merged. I created a separate PR so that it's hopefully easier to review.

Changes

Removed Singleton

I removed the StoreStatsUsageTracksEventEmitter singleton and replaced it with injected properties instead: 5a834ce.

In relation to this, I changed the My Store tab press detection to use viewWillAppear in b48094f to keep the StoreStatsUsageTracksEventEmitter instance within the StoreStats* classes. It felt incorrect to add the StoreStatsUsageTracksEventEmitter inside MainTabBarController. And subsequently, I realized that this causes duplication of "interaction tracking" since StoreStatsV4PeriodViewController. trackChangedTabIfNeeded is also executed when the merchant navigates back to the My Store tab. So I just removed it in 0316ac3.

Added Tracking to Old VCs

I noticed that there are OldStoreStats* classes now. I made sure to include the same interaction tracking to these classes.

• 8cab990
• ce0cfb2
• 197086b

Others

• I removed the notice call in 4d75603. That was mainly used for testing and playing with this algorithm.
• I applied the suggested changes from the Analytics Tracking Prototype #5503 PR: c83325e and ea5fa60.

Testing

1. Log in
2. Navigate to My Store
3. Do a few of the following:
   • Scrolling
   • Pull-to-refresh
   • Tapping on the bars in the chart
   • Changing the tab
   • Navigating to the My Store tab
   • Tapping on a product in the Top Performers list
4. Confirm that after performing at least 5 of the interactions within more than 10 seconds, a used_analytics Tracks event is logged.
5. Turn off the myStoreTabUpdates feature flag and repeat steps 3 and 4.

Author Checklist

• If it's feasible, I have added unit tests.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

[peril-woocommerce]

You can trigger optional UI/connected tests for these changes by visiting CircleCI here.

[peril-woocommerce]

You can trigger an installable build for these changes by visiting CircleCI here.

[jaclync]

LGTM! Code and testing with both feature flag states ✅