[firebase_core] Update `initiateOnDeviceConversionMeasurementWithEmailAddress` code sample

[Mercutio1243]

Bug report

Describe the bug When using the example project from the repository with android device, I get an exception:

Exception has occurred.
UnimplementedError (UnimplementedError: initiateOnDeviceConversionMeasurementWithEmailAddress() is only supported on iOS.)

Steps to reproduce

1. Download and run example project with Android device.
2. tab initiateOnDeviceConversionMeasurement button

Expected behavior

No error

Sample project

Example project from repository

[danagbemava-nc]

Hi @Mercutio1243, the error message indicates that the method you're calling is only supported on iSO. In your actual app, you should check if the platform is iOS before you use that method.

We will have to update the example to do that check.

[Mercutio1243]

Thanks! I am just using the example project to test my firebase setup. It will be an improvement, if it avoids these errors under Android.

[Lyokone]

Closing this since it's expected behavior.