[BUGFIX][IOS][LINKS] Update linking restorationHandler implementation for iOS12

[xzilja]

Summary

If project is used within Swift environment, there is an error thrown on iOS 12+ devices. Implementation needs to address this and this PR updates it as per official firebase https://firebase.google.com/docs/dynamic-links/ios/receive documentation for linking.

Fixes dynamic links for Swift based projects

Checklist

• Supports Android
• Supports iOS
• e2e tests added or updated in /tests/e2e/*
• Updated the documentation in the docs repo
  • LINK TO DOCS PR HERE
• Flow types updated
• Typescript types updated

Test Plan

Release Plan

[IOS][ENHANCEMENT] [LINKS] - Updated universal link handling implementation for iOS 12

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[mikehardy]

@Salakar something is not working on the detox patch in CI? https://ci.invertase.io/viewLog.html?tab=buildLog&buildTypeId=InvertaseOSS_ReactNativeFirebase_CiAndroidBuild&buildId=273

[Salakar]

CI back to normal, the failure relating to the detox patch was just a blip.

The current failure on here is because iOS is failing to build due to these changes; see the logs of ci.ios.build - build error from the logs:

And more errors above that on the logs

[xzilja]

Had a typo, build passed locally for test. Fingers crossed for CI now.

[mikehardy]

I verified this vs the docs (thanks for the link @iljadaderko ) and this looks clean. CI went green, I'm going to tag this for 5.4.x and +1 in it

I'll let it sit a couple days in case there any objections, then merge for release early next week I hope

[mikehardy]

@Salakar I don't have the Objective-C chops to adapt this v5 patch to your v6 code sadly, as it has skewed a bit, but you need to do the same thing right in this spot https://github.com/invertase/react-native-firebase/blob/master/packages/links/ios/RNFBLinks/RNFBLinksAppDelegateInterceptor.m#L55

[xzilja]

@mikehardy I'll open pr to v6 as well, will try to do it some time tomorrow

[Salakar]

This is not required at all in v6, internally we swizzle the app delegate methods directly. So there's no longer any need to add it to the users project app delegate either, package is just install and go.

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (v5.x.x@3146a2c). Click here to learn what that means.
The diff coverage is n/a.

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[mikehardy]

thank you @iljadaderko ! this will be in 5.4.3