Add install pixel

[samsymons]

Task/Issue URL: https://app.asana.com/0/1199333091098016/1208873240363373/f
Tech Design URL:
CC:

Description:

This PR adds an m.install.ios.* pixel that is sent when calling the exti URL.

Steps to test this PR:

1. Reset your simulator and run the app, look for m.install in the console, with the parameters reinstall and locale, which match the current state of your device - you should expect to see reinstall=false if you reset your simulator, then you can delete the app and reinstall it to get reinstall=true
2. Now kill and relaunch the app and check that you do not see m.install again

Definition of Done (Internal Only):

• Does this PR satisfy our Definition of Done?

Device Testing:

• iPhone SE (1st Gen)
• iPhone 8
• iPhone X
• iPhone 14 Pro
• iPad

OS Testing:

• iOS 15
• iOS 16
• iOS 17

Theme Testing:

• Light theme
• Dark theme

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Internal references:

Software Engineering Expectations
Technical Design Template

[samsymons]

This small delay isn't ideal; it's in place since the refreshAppRetentionAtb callback is waiting for the exti call, not the pixel call, so there is a chance that this could complete before the pixel call has had time to do its thing.

It would be better to wait for the pixel firing mock to have the right value, with a ~1 second timeout. I'll look at updating this.

[Bunn]

@samsymons I'm afraid there's an issue here, or I'm missing something when testing this.
No matter what I do, reset simulator, use a brand new simulator, I always see the pixel
Pixel fired m.install ["locale": "en-US", "reinstall": "true"] being fired.

After some investigation, I found out that the installCompletedWithATB is called before the fireInstallPixel which causes the ReturnUserMeasurement to return true

[Bunn]

Working as expected now, I was able to trigger both pixels, only once per install

Pixel fired m.install ["locale": "en-US", "reinstall": "true"]
Pixel fired m.install ["locale": "en-US", "reinstall": "false"]