Migrate Crashlytics to latest Firebase

[shostko]

just received a letter from firebase team:

We are writing to let you know that the Fabric Crashlytics SDK is now deprecated and will continue reporting your app's crashes until November 15, 2020. After this date, the Fabric Crashlytics SDK and beta versions of the Firebase Crashlytics SDK will stop sending crash reports for your app.
What happened?

We are replacing Fabric Crashlytics SDKs and beta versions of the Firebase Crashlytics SDKs with the generally available Firebase Crashlytics SDKs.
What’s next?

To continue using Crashlytics, make sure to upgrade your apps to the Firebase Crashlytics SDK versions 17.0.0+ for Android, 4.0.0+ for iOS, and 6.15.0+ for Unity before November 15, 2020.

Please take a look at the SDK upgrade instructions below for your app's platform: Android

The following project(s) linked with your account include apps that have enabled Crashlytics and not adopted the new SDKs:

Routine (instinctools-routine)

If you have questions or need any assistance, please reach out to support.