"warning CS0472: The result of the expression is always 'false' since a value of type 'int' is never equal to 'null' of type 'int?'" is thrown when importing "Notification Samples"

How to reproduce:
1. Create and open a new Unity project
2. Import the "Mobile Notifications" package
3. Import "Notification Samples" in the Samples tab of the "Mobile Notifications" package

Expected results: No warnings thrown in the Console window
Actual results: "warning CS0472: The result of the expression is always 'false' since a value of type 'int' is never equal to 'null' of type 'int?'" is thrown

Reproducible with: 2.3.0 (2021.3.32f1, 2022.3.13f1, 2023.1.20f1, 2023.2.0b18, 2023.3.0a14)
Not reproducible with: 2.2.2 (2021.3.31f1, 2022.3.11f1, 2023.1.17f1, 2023.2.0b14, 2023.3.0a10)

Reproducible on: Windows 11 22H2, macOS 13.5.2 (Intel)
Not reproducible on: No other environment tested